1 . Salad is good for you, generally speaking, so growing fresh greens in orbit seems like a winning way for space workers to stay healthy. New research suggests that as nutritious as space salad might be, it could pose something of a risk to astronauts.

The problem is growing leafy plants like lettuce (生菜) in space can come with a side dish of bacteria (细菌), according to a new study from a team at the University of Delaware. In tests on plants grown in modeled micro-gravity, they were shown to actually be more sensitive than normal to the Salmonella enterica (SE) (沙门氏菌).

We know that the International Space Station (ISS) is home to a lot of aggressive bacteria, and if these space virus were to cause widespread sickness in an astronaut crew, it would mean lives were at risk. “You don’t want the whole mission to fail just because of a food safety outbreak,” says plant biologist Harsh Bais from the University of Delaware.

Bais and his colleagues used a device to perform some clever rotation tricks in the lab, putting lettuce plants into a similar state as they would be in micro-gravity. They then added SE bacteria to the leaves. What was interesting — and surprising — was that the tiny stomata (气孔) in the lettuce opened up to allow the bacteria to get in. Ordinarily, the job of the stomata is to keep dangerous attackers out, while at the same time helping the plant to breathe.

The researchers then added a more helpful species of bacteria, one that typically protects plants from external stressors. Again, the defense didn’t work in micro-gravity — suggesting there’s something about this state that disables the chemical reactions that the lettuce would normally use to keep itself safe.

Add in what we know about space bacteria being particularly tricky, and this is a potential problem. The team behind the study wants to see a lot more research into making sure our foodstuffs are safe outside of orbit.

1. Why can’t lettuce be grown in ISS?

A．Its leaves takes up too much space.	B．It brings in illness-causing bacteria.
C．It is only a side dish to astronauts.	D．It can’t grow well in micro-gravity.

2. What is Bais’ attitude to growing plants in space?

A．Negative.

B．Sensitive.

C．Enthusiastic.

D．Unconcerned.

3. What did the tiny stomata do in the experiment?

A．They kept lettuce from breathing.	B．They ensure the safety of lettuce.
C．They failed to function as expected.	D．They stopped all bacteria coming in.

4. What is a best tile for the text?

A．SE, the Worst Bacteria in Space	B．Greens for Salad, a Risk in Space
C．Lettuce, Plant Samples Used in Space	D．Food Safety, a Key Problem in Space

2 . Bad news for banana lovers: A fungus (真菌) that’s particularly good at killing the fruit has finally reached Latin America — a major supplier of the world’s bananas.

Recently, officials in Colombia announced a national emergency after confirming the presence of this fatal fungus, known as Fusarium oxysporum Tropical Race 4 (TR4), in the country. This is the first time the fungus has been found in Latin America. However, the fungus isn’t new. Over the past years, it has been destroying banana plantations in Asia, Australia and East Africa.

Although this fungus isn’t harmful to humans, it is a “serious threat” to banana production. The fungus attacks the plants’ roots and blocks their vascular (维管的) system — the network used to transport water and nutrients (营养物) and finally kills the plants. Once the fungus finds its way into soil, it can’t be treated with fungicides, and it’s very difficult to remove.

What’s more, the fungus attacks the most commonly exported banana — the Cavendish banana. “For Western countries, the vast majority of the bananas we eat are from the same Cavendish subgroup,” said Nicolas Roux, a senior scientist.

Sarah Gurr, Exeter University’s chair in food security, continued to explained to Wired, “Cavendish bananas are in effect clones of their parents. So the similarity in their genes makes them easy targets of the disease. Actually, we are likely to lose the Cavendish banana.”

Officials reported that the TR4 fungus was found in a l75-hectare area in the La Guajira region of northern Colombia. The country has separated affected areas and destroyed some of them in an effort to fight the fungus. A number of ideas have come up to help save the Cavendish banana, including genetically engineering plants that will not be affected by TR4.

1. Why did Colombia announce a national emergency?

A．Because the TR4 fungus stops banana trees producing fruits.

B．Because there was TR4 fungus in Colombia.

C．Because a fearful fungus was spreading quickly.

D．Because Colombia had no bananas to transport to Europe.

2. What do we know about TR4 fungus?

A．It causes the death of banana plants.	B．It is dangerous for human beings.
C．It competes with banana trees for water.	D．It exists in the air to attack plants.

3. What makes Sarah Gurr worried about the Cavendish banana?

A．Their importance in global fruit supply.	B．Their poor ability to gain nutrients.
C．Their lack of genetic diversity.	D．Their wide planting in Latin America.

4. Which is the best title for the text?

A．Bananas crisis in Latin America	B．The best bananas in the world
C．Fungus harms plants	D．Banana-killing fungus reached Latin America

3 . What foods do you use to celebrate with your family? Do you eat something special on your birthday or holidays? Among the Hopi people, many foods for special celebrations are made from corn.

The Hopi people are Native Americans who live in Black Mesa, Arizona, USA. They grow special types of corn with long roots (根), which help the corn reach water in the ground in the hot and dry desert (沙漠).     1     In fact, in Hopi tradition, corn is the first solid food a baby eats.

The Hopi use each color of corn for something different. For example, blue corn is used to make some traditional Hopi foods. Piki is one Hopi food made with blue com. It is like a paper-thin, rolled pancake.     2     When a new baby is born, cobs (玉米棒子) of white corn are placed in the baby’s cradle (摇篮).     3     When girls grow up, they grind (磨碎) com for four days as part of their Coming of Age Ceremony. The Hopi also grind com by hand for wedding ceremonies.

    4     For example, in some Hopi villages, women walk down the Mesa to gather water and firewood every day. Men in those villages run up to 40 miles to their farms every day to grow corn, bean, and chili pepper crops. Other Hopi live in modern homes and use modern technology in their daily lives.     5     Corn is an important part of Hopi life today.

A．The Hopi people have a long history.

B．Corn is also used in Hopi ceremonies.

C．There are different types of corn as well.

D．Corn plays an important role in the Hopi diet.

E．Some Hopi today still live as they did hundreds of years ago.

F．White corn is used to wish a baby good health and long life.

G．But both groups still practice Hopi spirituality and other traditions.

4 . A Fish and Wildlife Service proposal would protect the whitebark pine as an endangered species. Whitebark pines can live for up to 1,000 years and grow at elevations (海拔) as high as 12,000 feet. Environmentalists had requested the government in 1991 and again in 2008 to protect the trees. A nonnative fungus (真菌) has been killing whitebark pines for a century. More recently, the trees have proved vulnerable (易受伤的) to tiny insects that have killed large areas of forest.

The whitebark pines have almost disappeared in some areas, including the eastern edge of Yellowstone National Park, where they are a source of food for threatened grizzly bears (灰熊). This makes the government’s declaration of the Yellowstone area’s grizzly bears as a restored species a lie.

After being blamed for not taking steps to protect the trees, wildlife officials in 2011 admitted that whitebark pines needed protection, but they didn’t act rapidly, saying other species faced more immediate threats.

A lawyer for the Natural Resources Defense Council, which made the formal request for protection in 2008, expressed his disappointment that it took so long but said the proposal was still worth celebrating.

The government’s proposal described the threats to the trees as immediate and said the whitebark pines were one of many plants expected to be harmed as climate change moves faster than they can adapt. “Whitebark pines survive at high elevations already, so there is little remaining habitat in many areas for the species to move to higher elevations in response to warmer temperatures,” Fish and Wildlife Service officials wrote.

Government officials are working with researchers and private groups on plans to gather seed from trees, grow them in greenhouses and then plant them back on the landscape, according to Fish and Wildlife Service biologist Amy Nicholas. A proposal of that nationwide restoration is expected by the end of this year. “We do have options to restore this species,” Nicholas said.

1. What do we know about whitebark pines?

A．They are long-lived, high-elevation trees.

B．They have a strong resistance to nonnative fungi.

C．The government used to care about protecting them.

D．They and small insects depend on each other for survival.

2. What makes the government’s announcement about grizzly bears a lie?

A．Grizzly bears are no longer threatened.

B．The whitebark pines have almost disappeared.

C．The population of grizzly bears has increased greatly.

D．The government is actually doing nothing to protect bears.

3. Which of the following would the lawyer agree with?

A．Better late than never.	B．All roads lead to Rome.
C．Never do things by halves.	D．The first step is the hardest.

4. What is Amy Nicholas’ attitude toward saving whitebark pines?

A．Irresponsible.

B．Doubtful.

C．Optimistic.

D．Uncertain.

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 . Looking for a big-leafed houseplant that will make a statement in your room and decorate yourhome? If so, then you’ve come to the right place!

Peace Lily

Extremely easy to look after, this popular, flowering plant is very tolerant and undemanding. It is a beloved houseplant for its large, glossy oval leaves and unusual white spoon-shaped flowers. Typically blooming in the spring, this lovely plant can effectively brighten up a living space.

African Mask Plant

This indoor plant is a smaller plant with large dark green leaves that are shaped like a heart. Native to tropical (热带的) parts of Africa, it prefers high heat and high humidity. That can be somewhat a tricky task for the average plant owner to achieve in their home, who is likely to have trouble duplicating (复制) these steamy conditions.

Snake plant

Commonly referred to as mother-in-law’s tongue, it is one of the easiest houseplants to take care of. With tall, twisting sword-shaped leaves that grow upright, it has air-purifying capabilities and can merrily grow in almost dark corners of the house. But the plant is poisonous to dogs and cats, so it’s wise to keep this plant away from them, if your pets are plant chewers.

Kentia Palm

Caring for the Kentia Palm plant is very straightforward, which can be neglected for weeks at a time. Quite enjoying a bit of shade, it has big leaves that grow from a narrow base and is great for filling a corner without taking up much floor-space. Place it in front of a blank wall, and its archingfronds (大型复叶) will cast beautiful shadows.

1. Which of the following requires an experienced plant owner?

A．Peace Lily.

B．African Mask Plant.

C．Snake plant.

D．Kentia Palm.

2. What do we know about the Snake Plant?

A．It poses little danger to dogs and cats.

B．It is better for purifying air than others.

C．It gets its name from a poisonous snake.

D．It grows well in shady areas of the house.

3. What feature do the listed household plants share?

A．Distinctive leaves.

B．Flowering season.

C．Growth temperature.

D．Striking size.

7 . If you’re interested in growing a small food garden at home, hydroponic (水栽法的) gardening provides a way to grow fresh, nutrient-rich food in a quickly-changing world with limited resources.

What is a hydroponic garden?

    1     Plants can grow indoors, year round, in less space than traditional soil- based gardens in it. This means if you live in a tiny apartment or don’t have an outdoor area, you can still grow fresh food.

How does hydroponic gardening work?

Plants need sunlight, water and nutrients to grow.     2     But the basis of hydroponics is rooted in growing the food in nutrient-enriched water. A hydroponic system can be programmed to ensure a plant receives sufficient water, nutrients, light and even the correct PH level to provide each plant with what it needs to survive and thrive.

What plants can grow hydroponically?

A variety of different foods can be grown in a hydroponic garden.     3     Similar to what you can grow in a backyard hanging garden, the more popular vegetables grown in hydroponics include leafy greens and lettuces (生菜) . However, more complex systems can produce fruiting vegetables such as tomatoes, cucumbers, peppers and more.

    4    

In addition to being able to grow food without soil and in small spaces, hydroponic gardening can contribute to solving social and environmental issues. In regions where people don’t have access to fresh vegetables, a hydroponic garden can be part of the solution. Hydroponic plants can grow 40% to 50% faster and produce 30% more than the plants growing in soil.     5     In some cases, you can grow produce that is even more nutrient.

A．Typically, plants get nutrients from soil.

B．What produce can a hydroponic garden offer?

C．What are the benefits of a hydroponic garden?

D．A hydroponic garden uses water instead of soil.

E．Microgreens are among the easiest plants to grow.

F．You can grow more produce in a shorter amount of time.

G．You can purchase a ready-to-go hydroponic garden or build your own.

8 . A famous book from the 70s called The Secret Life of Plants says that plants are conscious (有意识的).     1     In one study, plant exposed (裸露) to Mozart were healthier and grew faster than plants exposed to Jimi Hendrix. Some say these studies that claim plants have a taste for music are full of holes. But there is growing research on plant intelligence and plant communication.

Plants don’t have brains so they can’t think in the same way as humans.     2     They can even communicate this information to nearby plants. Researchers in England cut the leaves of cabbages (卷心菜).The threatened cabbages then produced a poisonous gas that protects them from certain insects.     3     Those healthy cabbages nearby seemed to be reacting to a warning from their cabbage neighbors.

    4     Of course, plants don’t have ears, but some scientists think they can feel vibrations. Italian scientist Dr Gagliano recorded clicking noises produced by corn seedlings (幼苗). She then placed these seedlings in water and played them similar sounds. Curiously, the corn seedlings grew towards the loudspeakers.

    5     Whether or not there is an intention to communicate is still up in the air. Whatever the case, plants are stranger and more wonderful than we can imagine.

A．But plants can sense their surroundings.

B．They even have a preference for music.

C．Some plants can communicate with sound.

D．The study also showed plants will row towards the sound of water.

E．So there is no doubt that plants arc communicating with their neighbors

F．Strangely, the uncut cabbages nearby also began to give off a poisonous gas.

G．The researchers believe plants are communicating with their neighbors through their roots.

9 . How to Control Weeds When Planting

No matter what you choose to grow in the garden, at some point, you will have to deal with unwanted plants, known as weeds.     1     Even a tomato plant can become a weed if it grows where you don’t want it to.

    2     Weeds can bring many problems. They steal nutrients and water. Weeds can also bring harmful bugs and diseases into your garden. Some weeds release chemicals that can slow the growth of nearby plants.

It is important to note that some weeds are not all bad. In fact, you can eat them. Dandelions (蒲公英) are also viewed as a weed by many people.     3     And you can eat or use nearly every part of the plant. But even other weeds can do good things in our garden. The roots of weeds can prevent the soil from being blown away by wind or washed away by rain.

However, left to grow on their own, weeds can take over a garden. To slow the growth of weeds, add a layer of weed-free, organic material to the top of your garden, around the plants.     4    

A simple and effective method of weed control is to break up the surface layer of the soil. But you must do this regularly. Do not turn the soil over.     5     If you turn the soil over, you give those seeds the light and air they need to grow. Probably the best way to fight some weeds is to eat them! Just make sure they are, in fact, eatable.

A．But their leaves are also full of nutrients.

B．This makes it difficult to reshape a garden.

C．A weed is just a plant growing in the wrong place.

D．This improves the soil and keeps weeds from growing.

E．Besides being unwanted, what else do weeds do to a garden?

F．Buried in the soil are weed seeds, waiting for the right conditions.

G．So, before we hurry outside to kill all the weeds, consider their good side.