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 . When micro-plastics end up in farm fields, the pollution can damage plant growth. But two young researchers now report that combining fungi (真菌) with certain farm wastes can partly overcome that problem.

May Shin, 20, and Jiwon Choi, 18, met in a research design class at the Fryeburg Academy, a high school in Maine. May had desired to explore how micro-plastics might affect the ecosystem. Jiwon was crazy about plants and fungi. The young scientists cooperated to test how long-lived plastics might affect farm crops.

Scientists have shown certain fungi can aid root growth and a plant’s nutrient uptake. Those organisms are named arbuscular mycorrhizal fungi (AMF). Certain farm wastes, like straw, can provide nutrients to plants and help stabilize their roots. Such wastes are also known as mushroom substrate (基质) and people often grow mushrooms in them.

May and Jiwon planted over 2,000 scallion (大葱) seeds in pots of soil. Half the seeds got soil polluted with micro-plastics. The rest grew in plastic-free soil. The plants then were further divided into four groups. The young scientists added AMF to the soil in one group. Another group had a top layer of mushroom substrate. A third group got both treatments. The last group got none. For three weeks, the pair tracked how many scallions sprouted (发芽) in each group and measured the plants’ height once each week.

About twice as many scallions sprouted in clean soil compared to that containing plastic bits. But among plants surviving in the polluted soil, a combination of AMF and mushroom substrate helped them out. Those getting both treatments grew 5.4 centimeters per week. That was faster than either of the treatments alone or those getting none.

Jiwon and May then looked at the plant roots with a microscope. Where AMF had been added, it grew into those roots. That increased the scallion roots’ surface area, May said, which should promote their uptake of nutrients. So “I see this project as coming up with a sustainable solution for plant growth in polluted soils,” said May.

1. Why did May and Jiwon work together?

A．To see the effects of long-lived plastics on farm crops.

B．To find the relationship between plants and fungi.

C．To design a research on the growth of plants.

D．To explore the way that the ecosystem works.

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

A．To prove the existence of micro-plastics.	B．To compare fungi with farm wastes.
C．To tell the advantages of farm wastes.	D．To provide some related information.

3. What aspect of the study is the fourth paragraph mainly about?

A．Its purpose.

B．Its design.

C．Its findings.

D．Its reasons.

4. How can AMF and mushroom substrate make plants grow faster?

A．By keeping the plants more resistant to pollution.	B．By allowing the plants’ deep area more freedom.
C．By making nutrients more available to the plants.	D．By exposing the roots to a larger surface area.