阅读理解 The longer the food is kept, the more likely it is to attract insects. Even foods stored in containers often attract bugs. To solve this problem, scientists have been working with different odors in an attempt 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. Unfortunately, however, using these smells might keep some people away too! A more promising repellent is citronella oil, which comes from a type of lemongrass. An experiment was done using this oil with a certain insect, the red flour beetle. Scientists sprayed 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 is quite ephemeral—it simply does not last very long. After a few months it loses its smell, and bugs no longer find it unpleasant. Scientists hope to improve citronella oil so that its scent remains strong for a longer time. It will also be necessary to make sure that the oil is not harmful to people, as scientists are not sure whether it is safe to use around food.( ) 1. What is the passage mainly about?A. Oil used in cooking.B. Ways of protecting food from insects.C. The behavior of a kind of beetle.D. Smells produced by different grasses.( ) 2. What does the author imply about the odors of garlic and pine?A. They last for a long time.B. They are not very strong.C. They can be unpleasant to people.D. They attract certain species of beetles.( ) 3. What are repellents?A. A food source for beetles.B. Machines used to get oil from plants.C. Substances used to keep insects away.D. Chemicals used to spend up plant growth.( ) 4. The underlined word“ephemeral”in Paragraph Three is closest in meaning to .A. weightlessB. short-livedC. overpricedD. not distinguishable
阅读理解
The longer the food is kept, the more likely it is to attract insects. Even foods stored in containers often attract bugs. To solve this problem, scientists have been working with different odors in an attempt 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. Unfortunately, however, using these smells might keep some people away too!
A more promising repellent is citronella oil, which comes from a type of lemongrass. An experiment was done using this oil with a certain insect, the red flour beetle. Scientists sprayed 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 is quite ephemeral—it simply does not last very long. After a few months it loses its smell, and bugs no longer find it unpleasant. Scientists hope to improve citronella oil so that its scent remains strong for a longer time. It will also be necessary to make sure that the oil is not harmful to people, as scientists are not sure whether it is safe to use around food.
( ) 1. What is the passage mainly about?
A. Oil used in cooking.
B. Ways of protecting food from insects.
C. The behavior of a kind of beetle.
D. Smells produced by different grasses.
( ) 2. What does the author imply about the odors of garlic and pine?
A. They last for a long time.
B. They are not very strong.
C. They can be unpleasant to people.
D. They attract certain species of beetles.
( ) 3. What are repellents?
A. A food source for beetles.
B. Machines used to get oil from plants.
C. Substances used to keep insects away.
D. Chemicals used to spend up plant growth.
( ) 4. The underlined word“ephemeral”in Paragraph Three is closest in meaning to .
A. weightless
B. short-lived
C. overpriced
D. not distinguishable
题目解答
答案
1.根据第一段中“scientists have been working with different odors in an attempt to find one strong enough to keep insects from going near food.”可知，科学家在研究使食物远离害虫的方法，后文都是围绕这个话题展开的。
2.根据第一段最后一句“Unfortunately, however, using these smells might keep some people away too!”可知，大蒜和菠萝的气味比较浓，人们不喜欢这些气味。keep away “使远离⋅⋅⋅⋅⋅⋅”。
3.repellent意为“驱虫剂”，可以使害虫远离一些物质。
4.根据后句“it simply does not last very long.”可知，该词指“保持的时间不长”。
1.B；2.C；3.C；5.B.
解析
文章主要讨论了科学家们为了解决食物吸引昆虫的问题，研究了不同的气味，包括大蒜和松树的气味，以及柠檬草油（香茅油）的使用。因此，文章主要关注的是保护食物免受昆虫侵害的方法。
步骤 2：分析大蒜和松树气味的暗示
文章提到，虽然大蒜和松树的气味可以驱赶昆虫，但它们也可能使一些人感到不适。因此，作者暗示这些气味可能对人类来说是不愉快的。
步骤 3：定义驱虫剂
驱虫剂是用于驱赶昆虫的物质。文章中提到的柠檬草油就是一种驱虫剂。
步骤 4：解释“ephemeral”的含义
文章中提到柠檬草油的问题是它“ephemeral”，即它不能持续很长时间。因此，“ephemeral”意味着“短暂的”。