1 . When gardeners grow varieties of plants in their beautiful gardens, they are happy to see beneficial insects like bees and butterflies surrounding the flowers. But as they take a closer look, they may find some plants are covered in black dots and filled with harmful insects or pests. Some gardeners may immediately reach for chemicals.     1     Although it may stop the insect problem, it will also threaten bees and butterflies which help the plants reproduce.

If you are wise gardeners, you should first take preventive measures to control the harmful insects.     2     Only when there are too many harmful insects, should pest control be considered. The first defense should always be the safest method available.

Prevention

As a rule, prevention is the best treatment. Inspect plants closely, including their leaves, before buying them from the store.     3    

When planting, space plants out to permit them to grow to their full size. Plants too close together can breed harmful organisms, like bacteria.

    4     They invite pests if permitted to remain on the ground. When you do see pests, wash them away. Use rubbing alcohol to remove some insects, or pick them off the plants.

Pesticides

If you decide a pesticide is necessary, choose it carefully and follow the directions and warnings on the product. Avoid using pesticides in extreme heat, on windy days, or when the plants are wet.     5     At the time, beneficial insects are inactive. You can consider removing flowers from the plants to lessen the risk that beneficial insects will come in contact with the pesticides.

A．But this is not wise.

B．In most cases, chemicals don’t help.

C．Treat the plants early in the morning or at night.

D．Also do remember the plants need nutrition and care.

E．Keep your garden free of fallen leaves, fruits and other wastes.

F．Do not bring any plants home that show signs of disease or pests.

G．The process starts with the idea that having some pests is acceptable.

2 . It turns out that sunflowers are more than just a pretty face: the ultraviolet (紫外线的) colours of their flowers not only attract pollinators (传粉者), but also help the plant regulate water loss, according to new research.

The yellow sunflower is a familiar sight, but it’s hiding something from the human eye — an ultraviolet bullseye (靶心) pattern, invisible to humans but not to most insects including bees. These bullseye patterns have long been known to improve the attractiveness of flowers to pollinators by increasing their visibility.

“Unexpectedly, we noticed that sunflowers growing in drier climates have flowers with larger ultraviolet bullseyes, and found that those flowers are able to keep water more efficiently. This suggests that these larger ultraviolet bullseyes help plants adapt to these drier environments,” says Dr. Marco Todesco.

Dr. Todesco and his colleagues grew almost 2,000 wild sunflowers of two species at the university in 2016 and 2019. They measured the sunflowers’ ultraviolet patterns, and analyzed the plants’ genes, and found that wild sunflowers from different parts of North America had ultraviolet bullseyes of very different sizes.

Larger floral ultraviolet patterns that have more of these compounds could help reduce the amount of water loss from a sunflower in environments with lower humidity (湿度), preventing too much water loss. In humid, hot environments, smaller ultraviolet patterns would promote the water loss, keeping the plant cool and avoiding overheating.

Sunflowers are planted for various purposes, including sunflower oil production, a roughly $20 billion industry in 2020. This research could help add to knowledge about how to attract pollinators, potentially increasing crop yields, says Dr. Todesco. “This work also helps us understand how sunflowers, and potentially other plants, better adapt to different areas or temperatures, which could be important in a warming climate.”

1. What do we know about sunflowers?

A．They don’t need pollinators.

B．Their flowers have special functions.

C．Their flowers can drive the insects away.

D．They can be grown in extremely cold areas.

2. What did Dr. Todesco and his colleagues do?

A．They analyzed 2000 kinds of sunflowers.

B．They planted sunflowers to carry out research.

C．They travelled to different parts of South America.

D．They helped people in North America plant sunflowers.

3. What is Dr. Todesco’s attitude to the research on sunflowers?

A．Positive.	B．Doubtful.
C．Negative.	D．Critical.

4. What can be the best title for the text?

A．A Hidden Function of Flowers of Sunflowers

B．Researchers Found a New Species of Sunflower

C．Sunflowers Can Change the Colours of Sunshine

D．Ultraviolet Bullseye Patterns Attract More Insects

3 . Are plants intelligent？Science is beginning to think so. In 2013, The New Yorker published an article that set the plant sciences world on fire, forever changing the way both the public and researchers looked at and studied the plant kingdom. The “Intelligent Plant” was previously unheard of.     1     But fast forward to 2019, there are now dozens of research papers and hours of video prepared and published by plant biologists discussing so many facts of plant intelligence.    2    

Communication: A lot of evidence suggests that plants, trees in particular, can communicate with one another     3     It is in some ways similar to the Internet we use. The idea of plants forming such a relationship to interact is considered as an evolutionary outcome.

Learning:     4     What if plants can learn from experiences like the dogs？The scientists designed experiments, whose goal was to prove whether plants could learn, an idea that seemed impossible. Ultimately, they succeeded in not only their experiments, but also in proving that plants can actually learn.

Memory: As research and experiment continue into the plant memory, people can’t help but ask the question “how can something without a brain have memories？” Studies have determined that plants can indeed learn and create memories.     5    

Figuring out the “plant brain” question is the logical next step. As more research comes in, the more it seems to indicate plant intelligence as a very real possibility.

A．Can plants be taught？

B．Can they remember things in general？

C．This communication occurs through underground networks.

D．It makes no sense to research plants communication methods.

E．They can display their memory recall through learned response.

F．The following behavioral characteristics are from the experiments.

G．Therefore, the plant biology community claimed it was completely baseless.