1 . Worldwide, there are more than a thousand mistletoe (槲寄生) species. They grow on every continent except Antarctica. They are parasites(寄生物) and live on the branches of their plant “hosts”, absorbing water and nutrients to survive. They accomplish this thievery via a specialized structure that infects their hosts. In fact, they infect plants of all kinds, including themselves—a number of species have been documented parasitizing other mistletoe species.

Yet despite their parasitism, mistletoe species may well be the Robin Hoods of plants.(Robin Hood is a character in old English stories who lives in a forest with a group of friends and steals money from rich people in order to give it to poor people.) They provide food, shelter and hunting grounds for other animals. Fallen mistletoe leaves release nutrients into the forest floor that would otherwise remain locked within trees, and this generosity benefits the food chain. “Yes, ecologically, they are cheats,” says David Watson, a community ecologist at   Charles Sturt University at Albury-Wodonga, Australia. But they share their wealth. “They steal these nutrients, and then they drop them,”   Watson says.

Mistletoe species depend critically on animals to get around. Most mistletoe fruits are berries containing a single seed that’s surrounded by a sticky layer. Roughly 90 bird species are known to consume mistletoe species’ seeds, so the birds can pass them to other trees on their bodies, or when they are eaten, seeds are passed through their waste. (There are exceptions:   Some mistletoe species make explosive fruits that send their seeds toward nearby trees,   reaching distances of 10 meters or more.)

Scientists have known that mistletoe species all have ancestors that were parasites not on branches, but on roots.   “They evolved over and over and over, and this understory,   root-parasitic, shrubby thing switched to being an aerial(meaning they infect above-ground plant parts, rather than roots), parasitic shrubby thing,” Watson says. Moving up the tree helped to solve a problem that all plants are faced with: competing for sunlight. Despite their parasitic nature, most mistletoe species still use energy from light to make their food.

1. What can we learn about mistletoe species according to paragraph 1?

A．They are highly independent.	B．They are harmful to their hosts.
C．They can be found on every continent.	D．They prefer to live on the roots of plants.

2. In what way are mistletoe species similar to Robin Hood?

A．They help poorly grown trees absorb more nutrients.

B．They have remarkable abilities to survive in the forest.

C．They live in the forest with other plant species in groups.

D．They steal and give food to many other living things.

3. How do most mistletoe species spread their seeds?

A．With the help of birds.	B．By making explosive fruits.
C．With the help of nearby trees.	D．By taking advantage of hosts’ seeds.

4. What does Watson tell us about the evolutionary development of mistletoe species?

A．They eventually evolved into shrubby plants.

B．Their habitats changed from roots to branches.

C．They tried to give up using energy from sunlight.

D．Their parasitic nature was formed in a gradual way.

2 . 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℃.

3 . Imagine if your houseplant was thirsty and it could tell you so. Chances are, it can—you just can’t hear it. According to the findings from researchers in Israel, tomato and tobacco plants stressed from lack of water or having their stems (茎) cut make sounds comparable in volume to normal human conversation.

The sound is kind of a snap (咔嚓声) and pop. While the frequency of the plant outcry is too high for our ears, they can likely be heard by insects, other animals and other plants.

The team started with healthy and stressed tomato and tobacco plants—the stressed ones were either unwatered for several days or had their stems cut. They recorded the group in an acoustic chamber (隔音箱) and then in a noisier greenhouse. They also used a machine-learning algorithm (算法) to distinguish between happy plants, thirsty plants, and cut plants.

The team found that stressed plants make more sounds than unstressed plants, with a stressed plant making 30 to 50 clicks per hour at seemingly random intervals. Unstressed plants were much less active.

“Water-stressed plants began making noises, and the frequency of sounds peaked after five days with no water before decreasing again as the plants dried up completely. The types of sound differed with the cause of stress,” according to a press release for the research. “The machine-learning algorithm could accurately distinguish between lack of water and stress from cutting and could also tell whether the sounds came from tomato or tobacco plants.”

The researchers explain that it’s unclear whether the sounds result from an effort to communicate—yet they note that the sounds have ecological and evolutionary meaning. “It’s possible that other organisms could have evolved to hear and respond to these sounds,” says Hadany. “For example, an insect that intends to lay eggs on a plant or an animal that intends to eat a plant could use the sounds to help guide their decision.”

1. What did the Israel researchers find?

A．Plants cry loudly when they are cut	B．Certain plants like to help each other.
C．Plants communicate as humans do.	D．Certain stressed plants make sounds.

2. What is paragraph 3 of the text mainly about?

A．Why a noisier greenhouse was used.	B．How the researchers did the research.
C．The importance of recording the plants.	D．The varieties of plants for the study.

3. When did water-stressed plants make the most noises?

A．The moment they were lack of water.	B．When the experiment began.
C．After five days of water shortage.	D．After drying up completely.

4. What do the researchers think of the sounds made by the stressed plants?

A．They are of much significance,	B．They help animals escape danger.
C．They affect the ecological balance.	D．They are mainly for communication.

4 . 听下面一段较长对话,回答以下小题。
1. What are the speakers discussing?

A．The man’s house.

B．The effects of global warming.

C．The man’s job.

2. What is always nice according to the man?

A．Animals can get more food.

B．Green can be seen all year round.

C．He lives by the sea.

3. What could farmers grow before?

A．Grass.

B．Vegetables.

C．Trees.

5 . Have you imagined making an attractive garden which will be the reason for your neighbors’ envy?

    1     But not every one of them has the talent for making it happen. However, if there’s one thing they DO know, it’s how to make a simple cup of tea. As for the used teabags, most of them find they’re on the landfill site, but no longer! Your used teabag can work wonders in your garden by your simply burying it.     2     Continue to read what it does.

If you have ever tried to grow some seedlings (幼苗), then you know that this can be quite challenging. Not all seeds can grow into seedlings, even though you have tried so hard. But don’t worry. Here is good news.     3     And what you need just involves a used teabag.

By burying a teabag in your garden, you will provide nutrition to the soil, offering necessary food to the plants. In this way, your plants will be healthier and grow quicker. This is because tea works as a natural fertilizer (肥料) for the soil. The teabag itself is usually made from fibres from the abaca plant, which is a type of banana plant. The bag breaks down with its contents.     4    

If you bury a teabag close to the roots of your plants, it will help store water in the soil. If there’s one thing important for plants, it’s water! What’s more, weeds are not wanted in your garden.     5     By burying a used teabag in the earth, you’ll make it a lot harder for the weeds to grow alongside your healthy plants.

A．A teabag is a great answer.

B．It does work though it sounds strange.

C．Making a beautiful garden requires efforts.

D．A beautiful garden is something most people enjoy.

E．There is one way to help your seedlings grow better.

F．A simple teabag is likely to do wonders for your seeds.

G．That will create a healthy environment for plants to grow in.

6 . 听下面一段独白，回答以下小题。
1. Why is it suggested not to buy from wholesalers?

A．They only sell seeds.

B．They don’t have good soil.

C．They don’t take good care of plants.

2. What is good soil?

A．Wet soil.

B．Hard soil.

C．Smelly soil.

3. How many suggestions are given?

A．2.

B．3.

C．4.

7 . With so many different kinds of plants out there, telling them apart can seem like an impossible task. But you don’t have to have a degree in botany to start putting names to the plants you come across. Learning to recognize various species begins with studying the plants’ unique physical features carefully and recording what you see.

    1     If you spot a plant outdoors and don’t have the first clue as to what it is, start identifying it by scanning your surroundings. In particular, consider the overall climate, the conditions of the terrain, and any nearby water sources. A quick glance should be able to tell you what you’re looking at.

Study the plant’s features carefully. Whenever you come across a species you’ve never seen before, stop and take note. Look over each of the individual parts, like the stems (茎，梗), leaves, and flowers.

    2    

Use viewing aids to take a closer look. A magnifying glass will allow you to zoom in and analyze a plant’s features in more vivid detail. Similarly, you may require a pair of binoculars or a telescopic lens when you want to inspect a particular specimen (样本) from a distance.     3    

Write down the plant’s key features.     4     Be sure to make mention of attributes like size, shape, color, and texture, as well as any unique patterns or other distinguishing marks. In order to learn to identify plants on your own, you’ll need to hone (磨练) your use of descriptive language to be as precise as possible.

Ask an expert to take advantage of their firsthand experience. Show your notes and any photos you’ve taken to a botanist, gardening specialist, or respected outdoorsman and see if they can help you discover the identity of a certain plant.     5     People who have spent years studying plants can often pick them out by sight or description.

A．Observe the plant carefully at first.

B．Take your environment into consideration.

C．Record each characteristic in your own words.

D．Judge the age and shape of the plants you have found.

E．Without these tools, you’ll be stuck doing a lot of guesswork.

F．You’ll have an opportunity to absorb a little of what they know.

G．Most plants can be grouped and distinguished by these structures.

8 . A major benefit of growing your own tomatoes is variety. If you visit a garden center, you will find seeds and small starter plants for yellow tomatoes, purple tomatoes, huge tomatoes, and even very small tomatoes.

    1    . The most important things are to give the plants plenty of water, well- draining soil, heat and light. It is best to grow tomatoes in a place that receives at least six hours of sunlight each day. Removing weeds will keep pests and diseases away while giving the plants enough nutrients to produce fruit.

Tomatoes grow best in soil with a pH level between 6.0 and 6.8. If the pH reading is lower than 6.0, you can add about 2 cups of dolomitic lime (石灰) into the soil for each plant.

If you want to grow really big tomatoes, try following these seven tips from expert growers: Select tomato seeds with names like Big Zac or Bull’s Heart.     2    .

Start seeds early indoors and re-plant them into larger containers several times before moving them outdoors.     3    , removing leaves from the bottom one- third of plants and burying stems up to the next set of leaves. This will produce stronger plants.

Remove new flowers that develop at the top of the plant when older fruits near the bottom begin to grow.     4    . Pay close attention! Observe the plants daily for posts and diseases. React quickly to prevent problems.

Remove the small growths where the plant’s stems and branches meet. This will prevent them from taking away nutrients and shading developing fruit under them.

    5     instead of letting them develop into a shorter, wider shrub (灌木).

Finally, water, fertilize and weed!

A．Plant them deep each time

B．Rich soil benefits the growth

C．Tomatoes are not difficult to grow

D．Skills are demanding in growing tomatoes

E．Cut back the plants to keep only one main branch

F．They are all genetically designed to produce large fruit

G．This will force the plant to produce fewer but larger tomatoes

9 . Welcome to Science on Sundays

Science on Sundays is a programme of free monthly science talks which always brings the latest discoveries in plant science, as well as research linked to the plant collection at the Botanic Garden, to the visitors in a 30-minute short period of time. The programme in April is about tulips(郁金香).

Introduction

Time: 2:30 pm on Sundays

Title: In Search of Wild Tulips

Objects: adults and children aged 12+

Speaker: Brett Wilson at University of Cambridge

Background Information

The planted tulips are a common sight in spring gardens around the world, but have you ever considered where wild tulips grow? The wild ancestors of our much-loved gardening varieties can mostly be found in the mountains and valleys of Central Asia, far from the Netherlands, where most tulips are grown and bred. At the Botanic Garden, we have a National Tulip Collection where we grow many wild species including plenty of species from Central Asia. Over the last four years, Brett Wilson has been using something learned from books and combining with fieldwork to understand the diversity of tulips, with a view of identifying which species are most at risk of extinction.

Come and listen to Brett speak about the research and the adventures that have occurred in our search to find and protect wild tulips in this remote corner of the world. These will be live face-to-face talks taking place in the Botanic Garden Classroom for those visitors with interest.

1. What do we know about Science on Sundays?

A．It focuses on plants.

B．It is a paid programme.

C．It appeals only to children.

D．It is a live broadcast on weekdays.

2. How does Brett Wilson understand tulips’ diversity?

A．By making assumptions.

B．By picking and collecting tulips.

C．By growing tulips in greenhouses.

D．By combining theory and practice.

3. What is the main purpose of the last paragraph?

A．To ask visitors to plant more tulips.

B．To call on visitors to listen to the talks.

C．To push visitors to take more botany classes.

D．To advise visitors to take adventure in remote areas.

10 . 阅读下面短文，在空白处填入1个适当的单词或括号内单词的正确形式。

The South China National Botanical Garden opened on July 11 in Guangzhou, Guangdong Province. It is the second national botanical garden in China,     1    (follow)the Beijing National Botanical Garden. With both gardens located in different climate     2     (zone), the species of plants that can be conserved in Guangzhou differ     3     (complete) from those in the Beijing garden.

With a total area of 333 hectares of exhibition and scientific research, the Guangzhou garden is the     4    (large) subtropical (亚热带的) botanical garden in the world, as well as one of China’s oldest institutions for botanical research and conservation. It is home     5     about 17,000 species of ex-situ (异地的) plants away from their natural habitats, including 643 rare and endangered plants     6     337 wild plant species on national key protection lists. So far, 36 species of rare and endangered plants, such as Camellia azalea and Dunnia sinensis,     7     (return) to the wild thanks to the garden.   

As one of the countries with the richest plant diversity in the world, China has more than 37,000 known species of land plants,     8     account for about 10 percent of the total in the globe. The     9     (found) of the national botanical garden system will enable the country     10     (protect) its plant diversity more effectively.