问题 单项选择题

阅读下面一段说明文,完成下列问题
什么是星云过去人们往往把天空中一切云雾状的天体都说成是星云。其实,离我们非常遥远的位于银河系以外的云雾状天体,并不是星云,而是与银河系类似的庞大的恒星系统。根据它们的外貌,人们有时也称其为河外星云,即银河系以外的星云。不过,实际上还是应当如实地把它们称为河外星系。河外星系的发现使我们知道,在天文学史上早期所发现的“星云”中,只有一部分是真正的星云。星云不但应当看起来是云雾状的,而且应当是真正由气体和尘埃组成的云雾状物质。这样的星云广泛地存在于银河系和河外星系之中。而我们现在所能看到的只局限于银河系的星云,即所谓银河星云。它的类型不同。形状不一,大小不等。其中有一种叫弥漫星云,具有不规则的形状,一般没有明确的边界。我们的太阳系就是在弥漫星云中形成的。但是,直接形成太阳系的,并不是整个的弥漫星云,而是由弥漫星云分解而成的星云块,即所谓球状体。形成太阳系的那个球状体,我们称它为太阳星云。

根据文章,下列“星云”的定义中,哪个是正确的

A.星云是在银河系中广泛存在的,由气体和尘埃组成的云雾状物质。

B.星云是在银河系和河外星系中广泛存在的,由气体和尘埃组成的云雾状物质。

C.星云是在银河系和河外星系中广泛存在的,由气体和尘埃组成的球状物质。

D.星云是在银河系中广泛存在的,由气体和尘埃组成的球状物质。

答案

参考答案:B

解析:[详解] 根据上下文,星云是在银河系和河外星系中广泛存在的由气体和尘埃组成的云雾状物质。故答案是B。

完形填空
Once there lived a farmer called Henry. He had a brother, Mike, in town who was an excellent gardener.  His skilland his beautiful trees were      everywhere.
One day, Henry went to town to visit Mike. "Look, my brother," said Mike, "Here is the best       tree from mygarden. Take it home and      it so that you, and your children, and your children's children can enjoy it.” Henry was      with the apple tree and went back home. The next morning, he began to      where he should plant it.
"If I plant it on the hill,” said he to himself, "the wind might catch it and      flown the fruit; If I plant it closeto the road, people who pass by will pick some of them; But if I plant it ..."
    he planted the tree in the comer behind his house, where no one else could notice it. But the tree bore(结出)no fruit the first year, nor the second. Then Henry sent for his brother and said to him       , “You have cheatedme. This is the third year and it bring me       but leaves.
When Mike saw where the tree was planted, he laughed and said, "You have planted the tree in such a cold cornerwithout        or warmth. How, then, could you expect flowers and fruil?"
小题1:
A.simpleB. famousC. similarD. common
小题2:
A.pearB.grapeC. appleD. banana
小题3:
A.sellB. washC. hideD. plant
小题4:
A.tiredB. patientC. pleasedD. popular
小题5:
A.learnB. wonderC. realizeD. understand
小题6:
A.putB. cutC. pushD. shake
小题7:
A.FinallyB. FirstlyC. LuckilyD. Certainly
小题8:
A.happilyB. angrilyC. kindlyD. carelessly.
小题9:
A.nothingB. somethingC. everythingD. anything
小题10:
A.airB. earthC. waterD. sunlight
单项选择题