阅读南宋词人陈亮的《梅花》，完成后面小题。
                                                                                                                                   梅 花 陈亮^①
                                                                                             疏枝横玉瘦，小萼点珠光。一朵忽先变，百花皆后香。
                                                                                             欲传春信息，不怕雪埋藏。玉笛休三弄^②，东君^③正主张。
      【注】①陈亮，南宋词人，一生极力主张抗金，反对投降，有着强烈的爱国精神。②三弄：指笛曲名“梅花三弄”。古有笛曲谢梅花之说。 ③东君：司春之神。

阅读下面的短文，掌握其大意，然后从短文后各题所给的A、B、C、D四个选项中选出可以填入相应空白处的最佳答案。

    Every day some people are killed while they are crossing the roads. 1 of these people are old people and children.Old people are often killed because they can't see or hear very well.Children are killed because they are not 2 .They forget to look and listen before they 3 the roads.

    A car or a bus can't stop quickly.If a car is going very fast, it will travel many meters before it stops.Some people don't always understand this.They think a car can stop in a few meters.It is difficult to 4 how fast a car is moving.The only way to cross the roads safely is to look both ways, right and left.Then if the roads are 5 , you can cross them.

①用酒精作燃料____

②实验室常温制取氧气____

③实验室制取二氧化碳____．

下列各数，属于科学记数法表示的是(      ).