问题
单项选择题
自然选择学说是达尔文进化论的核心原理。自然选择包括三个始终综合发生作用的因素，它们是（）
①变异性②遗传性③由繁殖过剩而引起的生存斗争④直立行走在进化过程中的作用
A．①②③
B．①②④
C．②③④
D．①③④
答案
参考答案：A
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自然选择学说是达尔文进化论的核心原理。自然选择包括三个始终综合发生作用的因素，它们是（）
①变异性②遗传性③由繁殖过剩而引起的生存斗争④直立行走在进化过程中的作用
A．①②③
B．①②④
C．②③④
D．①③④
参考答案：A
| 完形填空。 | |||
| 阅读下列短文，选择可以填入空白处的最佳选项。 My name is Martin. Years ago, I went to Michigan in the United States 1 an exchange student. I wanted to improve my English and learn about the culture there. 2 , I learned something else: When you are in trouble, you should believe love is here and there. On the 26th of August, my host family 3 me up from the airport in a big American car.  In the car, Idid not talk much 4 my English was poor. And I tried to answer their questions fast and go to bed early. The first week at my new home was OK. The following weeks, I 5 that the family was really strict and cold. One day, the son of the family 6 a baby parrot as a gift. Later on, the bird was really sick. But the child told his mom it was because every night, when 7 was sleeping, I poured some dirty water straight at the bird. My host mom 8 the lie (谎言) of her son and my sad life there started. Then one day the parrot was 9 . I had to leave the home. The family all thought I killed it. 10 , I made more friends in the school and I could move to live with them. They gave me love when I was in trouble. Now, I visit them once or twice a year. | |||
| ( ) 1. A. as ( ) 2. A. So ( ) 3. A. looked ( ) 4. A. when ( ) 5. A. wondered ( ) 6. A. received ( ) 7. A. somebody ( ) 8. A. told ( ) 9. A. dead ( ) 10. A. Sadly | B. for B. Besides B. turned B. b ecause B. described B. refused B. everybody B. gave B. ill B. Surprisingly | C. with C. However C. put C. unless C. wished C. gave C. anybody C. believed C. missing C. Unluckily | D. past D. Though D. picked D. if D. found D. offered D. nobody D. broke D. well D. Luckily |