问题 问答题 简答题

“门可罗雀”的典故出自什么著作?

答案

参考答案:“门可罗雀”的典故出自《史记》。

单项选择题

在地球之外,究竟有没有外星人两位美国学者撰文说,他们花了5年时间,在北半球天空捕捉到了37个可能是来自地球外文明的讯号.这两位学者是利用直径为26米的射电望远镜,来寻找由浩瀚宇宙深处发出的未知讯号的.他们以波长21厘米和10. 5厘米的电波对北半球天空的全部区域分别进行了三次和两次调查.许多从事探索地球外文明的科学家认为,波长为21厘米的电波在宇宙空间中极为普通,如果地球外文明要向其他星体发出讯号,就很有可能会使用这个波长.在探测时,他们试图寻找从极狭窄区域中释放出的强大电波.每次探测的时间约需200~400天,所以获得的观察资料十分庞大.经过筛选,才获得了这37个讯号,其中有5个讯号特别强烈.这些讯号大多数是沿着银河系分布的,在银河系内有着大量的恒星,是智慧生命可能存在的地方.然而,至今还未发现具有已接收讯号特征的电波源,且在这些电波的方向上,也没有特异的星体存在.这37个讯号果真是由外星人发出的吗科学家认为,如果在这37个讯号当中包括地球外文明的讯息,那么这就可能是由地球外文明发出的最强或最近的讯号.

“未发现具有已接收讯号特征的电波源”这句话的意思是____.

A.不知道已经接收到的讯号有没有电波源

B.已经接收到讯号但不能确定其电波源

C.不能确定电波发出的源头已经接收到了讯号

D.已接收到讯号但没有发现电波源的特征

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,选项中有两项为多余选项。

     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.   1   .

    Body image is a person's opinions and feelings about his or her own body and physical appearance.   2  . You appreciate your body for its capabilities and accept its imperfections.

    So, what can you do to develop a positive body image? 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 one 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. They care just as much as girls do about their body image.

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