D
The longer food is kept, the more likely it is to attract insects. To solve this problem, scientists have been working with different smells to find
one strong enough to keep insects from going near food. One possibility would be to use plants with strong smells, like garlic or pine, to keep insects away. Unluckily, however, using these smells might keep some people away too!
A more hopeful
repellent is citronella oil, which comes from a type of lemongrass. Scientists did an experiment using this oil with an insect—the red flour beetle. Scientists sprayed (喷洒) cardboard boxes with citronella oil and noticed that the beetles did not enter those boxes. They were much more interested in boxes that were not sprayed.
One problem with using citronella oil as a repellent, however, is that it does not last long. After a few months it loses its smell, and insects no longer find it unpleasant. Scientists hope to improve citronella oil so that its smell keeps strong for a longer time. It will also be necessary to make sure that the oil is not harmful to people, as scientists are still not sure if it is safe to use around food.
(
) 61. What is the passage mainly about?
A. Oils used in cooking.
B. The behaviour of a kind of beetle.
C. Ways to keep insects away.
D. Smells from different grasses.
(
) 62. What does the underlined word "one" in Paragraph 1 refer to?
A. Food.
B. An insect.
C. A scientist.
D. A smell.
(
) 63. Which is true about the smells of garlic and pine?
A. They last for a long time.
B. They are not always very strong.
C. They can be unpleasant to people.
D. They only attract beetles.
(
) 64. What does the underlined word "repellent" in Paragraph 2 stand for?
A. Food for beetles.
B. Machine used to get oil from plants.
C. Thing used to keep insects away.
D. Chemical (化学物质) for plant growth.
(
) 65. The following are unpleasant to insects EXCEPT
.
A. pine
B. flour
C. garlic
D. citronella oil
第Ⅱ卷(非选择题 共55分)
