1 . After tracking flowers on a prairie (草原) in Minnesota for 21 years, scientists reported that the plants reproduce more successfully in the year following a carefully controlled burn. Understanding the relationship between prairie plants and fire is important for preserving this ecosystem which is becoming rapidly smaller, says Stuart Wagenius, a conservation scientist.

Fire provides an additional advantage for the narrow-leaved purple coneflower (紫锥花), as Wagenius and his colleagues say. To really bloom (开花), they need a little help: Enter the fire. Between 1996 and 2016, Wagenius says his team tracked nearly 8,000 purple coneflowers on the Staffanson Prairie Preserve. In 9 of those years, they conducted controlled burns over 400 times. “In the summer after a burn, many more plants flower,” Wagenius says. “It is just a huge flowering festival.”

Purple coneflowers and many other prairie plants were previously known to bloom energetically after fires. However, the researchers said that fire also stimulated purple coneflowers to bloom at the same time in the summer after a burn. This meant that instead of being unconnected, the purple coneflowers were surrounded by potential mates and went on to produce nearly double the number of seeds compared with other years. Wagenius says it’s not yet clear exactly how fires signal the flowers to get busy.

The new findings may help the people who manage prairies to better understand the different ways that fire affects the plants growing in these habitats, said Kathryn Yurkonis, a grassland ecologist who was not involved in the research. However, Yurkonis added, it remains to be shown how the fires influence the purple coneflower population. “This paper implies that making more seeds would mean more seeds would land on the soil and enter the population of plants — but they don’t actually examine that step,” she said. “I’d be curious to see whether this actually translates to more purple coneflowers.”

1. What is the basis for the research?

A．Prairies are easy to disappear.	B．Plants on a prairie are diverse.
C．Fire relates positively to prairie plants.	D．Without fire, flowers won’t bloom.

2. What does the author intend to convey with figures cited in paragraph two?

A．Wagenius’s team was committed indeed.

B．Samples of flowers were rich in number.

C．Time spent on the research was long.

D．The findings were relatively convincing.

3. What is paragraph 3 mainly about?

A．The result of plants being unconnected.

B．The influence of fires on prairie plants.

C．The process of prairie plants’ growing after fires.

D．The reason for plants’ blooming at the same time.

4. What is Kathryn Yurkonis’s attitude to the research finding?

A．Uninterested.

B．Prejudiced.

C．Objective.

D．Opposed.

2 . More than half the world relies on rice as a main food source. Yet the crop faces an worrying future as global warming increases the Earth’s temperature and adds to more storms, droughts and heat waves, because rice is sensitive (敏感的) to climate extremes and grows in places already experiencing many. Any disturbance to that food source can cause great problems.

The latest report from the Intergovernmental Panel on Climate Change—which brought together 234 scientists to collect recent climate studies—warned that human-caused global warming is happening at an extraordinary pace and is adding to the deadly floods, heat and droughts that we’re already witnessing. And those events result in major risks to farming.

“Higher temperatures lead to increased water loss, resulting in soil drying, increased plant stress and impacts on agriculture, especially in regions where large amounts of rainfall are not expected,” the report states.

If greenhouse gases are not reduced, about a third of global land areas are expected to suffer from at least moderate drought by the end of the century, the report concludes. Some changes like sea-level rise are already locked in.

Rice is especially sensitive to these changes. Rice often grows in ecosystems, such as deltas (三角洲), that have low sea-level and are easy to be influenced by rising seas. Any additional temperature increase could cause sea water into the filed where a healthy crop can develop, scientists say.

A 2018 study in the Archives of Agronomy and Soil Science found that an increase in the frequency and seriousness of hot weather could reduce rice outputs by up to 40% by the end of this century.

“Most of the world’s rice is currently grown in regions where existing temperature is already close to the most suitable range for rice production,” the study states. “Therefore, any further rise in temperature or short period of high temperature during sensitive growth stages will be disastrous.”

1. Why is rice particularly weak to climate change according to the passage?

A．Rice requires large amounts of rainfall.

B．Rice is grown in regions with low sea levels.

C．Rice is hard to live in places with extreme climate conditions.

D．Rice is grown in regions with high levels of greenhouse gases.

2. What is the main concern for rice production in the future?

A．Rising sea levels

B．Increased frequency of storms

C．Global warming and climate change

D．Reduction in greenhouse gas emissions

3. What attitude does the last paragraph show us?

A．Pessimistic

B．Optimistic

C．Uncertain

D．Encouraging

4. Which is the best title for the passage?

A．Rice Output Is Decreasing Heavily.

B．Climate Change is Caused by Greenhouse Gas.

C．Climate Change Resuits in Low Output of Rice.

D．Greenhouse Gas Has Great Effect on Rice Growing.

3 . House Plants That Are Easy to Grow

Jessica Damiano is an expert at taking care of plants. She writes stories about how to keep plants in good condition.     1     She said it is not that she does not know how to take care of these house plants, but that she just paid no attention to them. She added that the plants are among the hardest to keep alive.

As a result, Damiano chooses house plants that need the least amount of care for her home.     2     She also raises plants that grow well with limited light, and can be moved around. Also, these sorts of house plants are best for beginners to grow.

Chinese evergreen is a beautiful house plant that does well in low-light conditions. Damiano said all you need to do is keep the plant’s soil lightly wet at all times and fertilize (施肥) every other month over the winter and every month for the rest of the year.

The cast iron plant is as strong as its name sounds. Damiano said it does not even want your attention.     3     It prefers electric light or light from a north-facing window. Let the soil dry out between waterings and fertilize every other month in summer and autumn and just once during the winter.

One house plant, the aloe plant, can be used for treating burns.     4     That liquid (液体) not only protects burned skin, but also the plant. Just place it by a window that provides bright, indirect sun light and water it every three weeks, and less often during winter.

Similar plants called succulents share aloe plants’ ability to store water within their leaves.     5     Most also share aloe plants’ lack of requirements, making them a good fit for new plant parents.

A．Avoid providing too much sunlight.

B．But even she has killed house plants.

C．These house plants usually need much attention.

D．She looks for plants that grow well with very little water.

E．There are many other house plants that need little water and sunlight.

F．These sorts of plants usually do well where conditions are dry and warm.

G．When necessary, just cut open a leaf and use the juice from within on an injury.

4 . This is the time of year when many gardeners are harvesting tomatoes. Gardening expert Jessica Damiano recently reported about the many pictures of strangely shaped tomatoes sent to her from fans of her gardening advice.     1    . The good news, Damiano said, is that there is nothing wrong with the strangely shaped fruits.     2    . Their unusual appearance does not affect their taste or nutritional value.

    3     If you have ever cut open a tomato, you know they are divided into internal (内部的) parts, called locules (小室). Most tomatoes have about four or five locules; other kinds of the fruit, like cherry tomatoes, contain two or three. But when a plant experiences extreme (极端的) temperature, cell division in the developing fruit can go off track. Temperatures over 32℃ during the day and 27℃ overnight can lead the tomato to form an extra locule. But there is not enough room inside a tomato for the extra part, so it grows on the outside of the fruit.

Not every tomato on an affected plant will be deformed (改变形状), however. What are the possibilities? Under the right conditions (temperatures that are too hot or even too cold), this could affect one or two tomatoes per plant, depending on where they are in the development process and what the (weather) conditions are, said Timothy McDermott, a professor at Ohio State University. The possibility of one of your tomatoes developing a locule oddity (怪异) is about one in a thousand, McDermott said.     4     But, Damiano noted, heirloom (原种) kinds seem more likely to have this genetic mutation (基因变异) than hybrids.

And, when harvesting your crop, remember:     5    

A．select the good-looking ones.

B．Any tomato can grow an extra locule.

C．the funny-looking tomatoes taste just as good!

D．What causes the unusual appearance of tomatoes?

E．Unless otherwise diseased, they are perfectly good for eating.

F．She said people sometimes question if the tomatoes are okay to eat.

G．Provide shade for your plants when temperatures are predicted to remain above 32℃.

5 . Imagine you are on a beautiful tropical beach. The blue water shines in the sun, and the sand is warm under your feet. You notice a small fruit in the sand. It looks like a little green apple. You pick it up and smell it... it smells sweet. But whatever you do. Don’t take a bite!

This is the fruit of the manchineel tree. It is the most poisonous tree in America. You can find it in Florida, as well as in the Caribbean, Mexico, and Central America.

If you were to eat the fruit, it would taste delicious. But then your mouth would start to burn. Your throat would tighten and make it difficult to breathe. You could even die.

The fruit isn’t the only risky part of the manchineel tree. The tree is full of milky white sap. Sap is a liquid that flows through a plant, like blood flows through a person. The manchineel’s sap is hazardous. If it gets on your skin, it will cause painful blisters. So don’t try to cut down these trees, because you could get sap all over you!

And if you try to burn manchineel wood, the smoke will choke and blind you.

Manchineel trees are dangerous, but they’re also an important part of the environments where they grow. Manchineels protect beaches with their strong roots. The roots help stop sand and soil from washing away. This is good for the plants, animals, and people living nearby. There aren’t many manchineel trees left in the world. So even though they’re harmful, people are trying to protect them. Still, if you see one, stay away!

1. What do we know about the manchineel tree?

A．It looks ugly.	B．Its fruit is dangerous.
C．Its fruit tastes terrible.	D．It grows in cool places.

2. What does the underlined word “hazardous” in Paragraph 4 probably mean?

A．Clear.	B．Smelly.
C．Sweet.	D．Unsafe.

3. What is the author’s purpose in writing the text?

A．To help people choose fruit.

B．To introduce the manchincel tree.

C．To improve people’s sense of safety.

D．To attract people to tropical beaches.

6 . Mangroves (红树林) grow on the boundary between land and sea. Rooted in the soil exposed to sea water, they support a rich biodiversity and provide a valuable nursery for some sea animals like fish, supporting the food security of coastal communities. More importantly, they can resist natural disasters, thus keeping communities and structures safe and sound.

Over time, these exceptional trees have adapted to withstanding or recovering from the impact of natural disasters such as storms and tsunamis (海啸). When waves pass through mangrove forests, the above-ground roots and branches of the trees reduce wave height and energy. This decreases the waves’ ability to consume the soil and damage coastal buildings, while reducing the risk of flooding for low-lying areas behind the mangrove forests. Over a distance of 100m, wave heights can decrease between 13% and 66%. Over a distance of500m, mangroves can reduce the height of waves by 50% to 99%.

Dense (茂密的) mangrove forests also reduce wind speeds locally, which has the added advantage of preventing waves in and immediately behind the mangroves. This can potentially reduce its hazard to nearby facilities.

There is growing evidence that mangroves can reduce the impact of tsunamis by lowering the destructive energy of water flowing inland. This was the case notably during the Indian Ocean tsunami in 2004. Mangrove belts, which are several meters wide, have been shown to decrease tsunami wave height by between 5% and 30%. Wide and dense mangrove forests can also limit the area flooded by tsunamis, However, tsunamis over 4 meters deep may be taller than the mangroves and able to damage or even destroy these trees. Therefore, engineered structures are rarely built to the height of mangroves.

Some mangrove trees can grow up to 60m in height, depending on the species, climatic conditions and available nutrients. Some mangroves also exist as short plants. They are found in the coastal areas of the Americas, Africa, the Middle East and Asia-Pacific. It is estimated that more than three-quarters of the world’s mangroves are now threatened by coastal development, overexploitation, waste disposal and other pressures.

1. What enables mangroves to reduce wave height and energy according to paragraph 2?

A．The surrounding soil.	B．Their rich biodiversity.
C．The high-lying areas ahead.	D．Their natural structure.

2. What does the underlined word “hazard” in paragraph 3 probably mean?

A．Response.

B．Contribution.

C．Attachment.

D．Threat.

3. Why does the author mention the Indian Ocean tsunami in 2004?

A．To prove mangroves can fight against tsunamis.	B．To say engineered structures are easily destroyed.
C．To show the harmful results brought by tsunamis.	D．To explain the gradual formation of coastal disasters.

4. What can be a suitable title for the text?

A．Mangroves: the Mirrors of Natural Disasters	B．Mangroves: the Heroes of Coastal Protection
C．Mangroves: Seriously Threatened Plant Species	D．Mangroves: Shelters for Endangered Sea Animals

7 . My husband, Dave, who teaches Botany (植物学), always plants things. He has planted trees anywhere we have lived and is proud to see they are flourishing and providing shade and beauty for whoever lives there.

I also love planting, especially the harvest. But I hate weeding (除草). I remember one of our first gardens in Kansas when I was attacked by the hugest grasshoppers (蚱蜢) I had ever seen while weeding our little garden.

Now, our growing efforts at our new home are vegetables. We are enjoying the garden we have created. It’s large but manageable with daily care. We use methods to minimize weeds. We have the time to keep up with the watering and weeding. I find I don’t hate that anymore.

There is something satisfying about pulling grass, and violets that are growing where we don’t want them, and unnamed weeds that are affecting the growth of what we want. I find that my relationship with gardening is turning into a true romance that has a rosy future.

It’s all about time, environment and attitude. Being in my eighties, I have the time to be patient for results, to enjoy the hope for future harvest, and I have the knowledge that comes from experience. I find a lot to love about growing things and about growing older.

1. What does the author’s husband take pride in?

A．Teaching.	B．Weeding.
C．Planting trees.	D．Growing vegetables.

2. How did the author feel when seeing grasshoppers from the weeds?

A．Calm.

B．Excited.

C．Bored.

D．Frightened.

3. What can we infer from paragraph 4?

A．Weeds are growing wildly.	B．The author begins to enjoy weeding.
C．The author finds new ways to weed.	D．Weeds balance the garden.

4. What does the author say about growing old?

A．It is a time to start work.

B．It is a stage of showing pity for the lost past.

C．It lets people become patient and wise.

D．It makes learning knowledge difficult.

8 . 听下面一段较长对话，回答以下小题。
1. Which plants are the woman’s favorites?

A．The red ones.

B．The pink ones.

C．The purple ones.

2. Why can’t the woman grow many plants in the house?

A．She is too busy to feed them.

B．There isn’t enough water.

C．There isn’t enough light.

3. What does the woman plan to do next?

A．Make a meal.

B．Water her plants.

C．Reach for a glass container.

9 . 听下面一段独白，回答以下小题。
1. What is the most important thing when planning a garden?

A．Growing what one loves.

B．Picking the right soil.

C．Choosing the location of the garden.

2. How many things do people need to plan before starting a garden?

A．5.

B．4.

C．3.

3. What is the advantage of growing from young plants?

A．They’re less expensive.

B．They grow more easily.

C．Their fruits will grow big enough.

4. What does the speaker suggest people do in the end?

A．Plant right before the growing season.

B．Ask an expert for the right soil.

C．Enjoy the process of planting.

10 . Sunflowers have increasingly become popular on social media. People enjoy the bright yellow flowers and take pictures of themselves in bright fields of sunflowers, which are called “sunflower selfies.”     1     So they are often grown for their seeds or to make oil.

Actually, it is easy to grow your own sunflowers. Here are some instructions.

Do you want to start growing sunflowers from seeds?     2    . It will help them come up earlier. Meanwhile, choose a place outside where the plants will be able to enjoy at least 6-8 hours of direct sunlight each day.

    3     When loosening, you should remove any rocks. Additionally, it is better to mix a large amount of compost (堆肥) into the soil, which will provide important and lasting nutrients all season long.

Then, plant each seed into soil apart. Keep the soil wet, but not too wet, until the seeds begin to grow. During the growth process, you should water regularly the plants. When they grow up, it is best to put up some shelves to protect the plants from strong winds.     4    

When seeds will start coming out of the head, it is time for harvest. Cut the flowers off and put them into a bag or container. In this way, the seeds will not fall out. Then remove the seeds by rubbing flowers with your hands or a hard brush over a container.

Finally, you’d better select those full seeds for food.     5     If you like salted seeds, boil them in hot salted water for 1.5 hours or so. After they dry, you can roast them in the oven. Set the temperature and cook the seeds until they are brown. Then, you will enjoy the delicious food.

A．Equally attractive is the delicious taste.

B．Sunflower seeds may be eaten cooked or uncooked.

C．You can also tie the plants to something tall for support.

D．Some kinds of sunflowers can grow up to three meters tall.

E．It is important to loosen the soil before the seeds are planted.

F．Put the selected seeds in room-temperature water for 2-8 hours.

G．They will develop long roots that work their way deep into the ground.