题干

阅读《地球大气圈》节选文字,完成后面小题。

       ①我们翘首望天,似乎高不可及。其实我们所看见的这个“天”,本是“地”的一部分——地球大气圈的低层。它的高度不过十几公里,宇宙火箭很容易就穿越了这个高度,这时再回顾地球,蓝天却已跑到我们的脚下,似轻烟,似薄雾,更仿佛是一层蔚蓝色的软纱裹在地球的表面。

       ②大气圈看起来仿佛空若无物,实际上是壁垒森严,将地球重重包住。岂止是面纱,简直是屏障,是铜墙铁壁,对地球起着重要的保护作用。

       ③1976年,在我国吉林省落了一场陨石雨,成为自然界罕见的珍闻。假使没有大气,这种从天而降的陨石将成为家常便饭,给地面造成极大毁坏。正是由于大气圈的保护,高速冲来的陨石因与大气剧烈摩擦,减慢了速度;并因摩擦产生的高热影响,绝大部分陨石在100多公里的高空就化为灰尘和气体,只有极少数到达地面,而且已是强弩之末,一般不会造成什么危害了。

       ④从天外向地球袭来的还有强烈的紫外线。假使没有大气,过多的紫外线将使地球上的生命无法生存,是大气圈保护了我们。在大气圈中离开海面20-35公里这一带含臭氧较多。所谓较多,也不过占到四百万分之一左右。但这点臭氧已足以使大量紫外线被吸收,才使得地球上各种生物免受过多的紫外线伤害;剩下少量的到达地面,对我们来说有杀菌防病作用,反而变得无害而有益了。

       ⑤那些极其稀薄的为地球磁场所控制的带电粒子组成的高层大气,也有保护地球的作用。它能使宇宙中那些以高速冲向地球的粒子流偏转方向。

       ⑥地球大气圈的存在,不仅保护了我们,还是生命得以发生和发展的重要条件。假使没有大气,就没有灿烂的云霞,更没有生命的喧嚣,而将是白天酷热,夜晚严寒,天上是黑洞洞的,地下是一片荒凉。

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同类题2

下面文章中有5个段落需要添加首句。请从以下选项(A、B、C、D、E和F)中选出适合各段落的首句。选项中有一项是多余选项。

A. Be a good listener.  B. Care about the details.

C. Strike up a conversation. D. Make time for friendships.

E. Reach out to the newcomers.    F. Avoid causing inconveniences

    Develop Better Relationships with Neighbors

    Good neighbors are a lot like electricity or running water:we don't know how much we depend on them until we don't have them. They make our lives more pleasant and give us a sense of who we wrte, both as an individual and as a member of the community. Here is how to develop your relationships with these very important people in your life.

    ____ Often neighbors don't even know each other's names. But it's okay to be the one to break the ice , even if you've lived next door for years.Most neighbors enjoy making small talk with the folks on the other side of the fence. So as you see them at work in their yards, smile, wave, and say hello. Ask how their kids are (whether they're babies or in college), whether they could use an extra cucumber from your garden, or what they think of the price at the local supermarket.

    ____ These days, the old Welcome Wagon is a thing of the past. But your new neighbors may be feeling lonely and unsure, especially if they're far from home, and might appreciate a friendly face bearing fresh-baked chocolate cakes. If they have kids, tell them where the children in the neighborhood live. Recommend the best places to eat and sleep. Invite them over for coffee or tea when they get settled, give them your number, and point to your house as you say good-bye.

    ____ Return anything that you borrow from a neighbor, such as tools, in good repair and as soon as you've finished with them. Replace anything that belongs to your neighbor that you, your children, or your pets break or soil. Make sure that your car is not blocking their doorway. Such random acts of consideration will have your neighbors talking—and the talk will be good.

    ____ If you value a friendship with your neighbors, spend time with them. What better way to meet your neighbors than to invite them to an informal barbecue, pool party, or holiday open house? Better yet, you might even consider throwing a get-together in their honor. Deliver the invitations in person to everyone who lives on your street and chat with each for five minutes before moving on to the next house. This way, you will get an idea of what your neighbors are like so that you can plan for appropriate food and music.

    ____ In a good relationship, it's really the little things that count. Help to bring in the mail for the elderly neighbor when there is a heavy rain. When your neighbor gorgets to take in his rubbish cans, roll them back into his yard. If you're truly concerned, you'll know when your neighbor needs some cheering up—a bunch of flowers or a helping hand when it's needed. All it takes to develop your relationship with neighbors is the respect for their feelings.