问题 单项选择题

下列关于生物进化的叙述,错误的是()

A.生物的种间竞争是一种选择过程

B.化石是研究生物进化的重要依据

C.突变的可遗传性阻碍生物进化

D.外来物种入侵能改变生物进化的速度和方向

答案

参考答案:C

解析:

生物的种间竞争是一种相互选择,共同进化过程,故A正确。化石是生物保留下来的遗体、遗物,能反映生物的进化,故B正确。突变提供选择的原始材料,有利生物进化,故C错。外来物种由于适应性强,无天敌,改变当地生态平衡,故D正确。

考点:本题考查生物进化相关知识,意在考查考生能理解所学知识的要点,把握知识间的内在联系能力。

阅读理解

阅读理解

根据短文内容,从短文后的选项中选出能填入空白处的最佳选项.选项中的两项为多途选项.

     Many people think of guys as being carefree when it comes to their appearance. But in fact, a lot of

guys spend plenty of time in front of the mirror. They care just as much as girls do about their body image.

     Body image is a person's opinions and feelings about his or her own body and physical appearance.    1    . You appreciate your body for its capabilities and accept its imperfections.

        2    . Here are some ideas:

     Recognize your strengths. Different body types are good for different things. What does your body

do well? Maybe your speed, strength, or coordination makes you better than others at a certain sport.

That may be basketball, table tennis, mountain biking, dancing, or even running. Or perhaps you have

non-sports skills, like drawing, painting, singing, playing a musical instrument, writing, or acting, 

          3    .

    Exercise regularly. Exercise can help you look good and feel good about yourself. Good physiques

(体形)don't just happen.     4    . A healthy habit can be as simple as exercising 20 minutes to 1 hour

three days a week. Working out can also lift your spirits.

     Respect your body! Practicing good habits - regular showering; taking care of your teeth, hair, and

skin; wearing clean clothes, and so on -can help you build a positive body image. 

    5      . Your body is just one part of who you are. Your talent for comedy, a quick wit (智慧), and all

the other things make you unique. So try not to let small imperfections take over.

A. Use this as an opportunity to discover what you're good at.

B. Be yourself.

C. Having a positive body image means feeling satisfied with the way you look.

D. Just explore talents that you feel good about.

E. They take hard work, regular workouts, and a healthy diet.

F. The good news is that self-image and body image can be changed.

G. So, what can you do to develop a positive body image?

单项选择题