Question

Do you have trouble getting started in the morning? Do you have problems learning early in the day? If you do, you are not alone, _1.__ They learn better at night than they do in the morning.

To investigate when cockroaches(蟑螂) learn best, researchers at Vanderbill University tested the insects for which odor(peppermint 薄荷 or vanilla 香草) they preferred. Most cockroaches preferred the smell of vanilla to that of peppermint at all times. __2.__ Therefore, the scientists trained the cockroaches to prefer the peppermint smell by rewarding the insects with a taste of sugar water when they approached a peppermint smell. _3.__

When the cockroaches were trained at night, they remembered the new associations(peppermint＝sugar water; vanilla＝salt water) for up to 48 hours. However, if the cockroaches were trained in the morning, they quickly forgot which smell went with which water. __4._

So, cockroaches learn better at night than they do in the morning. _5._ Because of this, it is likely that information they gather at night will be more useful to them. These experiments provide some clues about the interactions between body rhythms, learning and memory.

A．When these insects moved toward a vanilla smell, on the other hand, they were punished with a taste of salt.

B．This result thus shows that the time when they were trained decided the effect of their learning.

C．They are often more active and tend to search for food during the night.

D．They were also found to like sugar water, but not salt water.

E．Cockroaches have the same problem!

F．But they prefer warm conditions found within buildings.

G．Pest species adapt easily to their environment.

 

Answer 1

1.E

2.D

3.A

4.B

5.C

【解析】科學(xué)家通過試驗說明了蟑螂更適于夜間行動，在夜間它們身體的各個機(jī)能都好于早晨，所以工作效率也會更高。

1.E　前面說到你不再孤單，即還有別人像你一樣不喜歡早起、不喜歡早上學(xué)習(xí)，所以接下來就要說有同樣問題的人或物是誰了。故選E項。

2.2】D　根據(jù)下文中“with a taste of sugar water...”可知選D項。

3.3】A　本段介紹了蟑螂對糖水和鹽水不同反應(yīng)的試驗，前面介紹了糖水，接下來肯定要說到鹽水。故選A項。

4.4】B　此處是一個總結(jié)句，是對以上試驗的一個結(jié)論。故選B項。

5.5】C　試驗證明了蟑螂在夜間的反應(yīng)更快，所以效率也會更高。故選C項。