给加下划线字释义。

赍书飞报紧急军情事 ____

果然仗义疏财，名不虚传____

你将赎来用度____

阅读下列短文，从下面每小题的A.B.C .D四个选项中选出最佳选项。

    It is easier to float in the ocean than in a swimming pool. Do you know why?

    Ocean water is full of salt - and salt water can hold up more weight than fresh water. See for yourself! (Ask an adult to help you.)  You will need: 3 cups warm water; A wide-mouth jar（罐）; Salt; A spoon; A potato. You will do: 1. Pour 1.5 cups of warm water into the jar. 2. Add 1/3 cup of salt.  3. Stir(搅拌) until the salt is completely dissolved(完全溶解) 4. Add another l.5 cups of water. Pour it slowly over the back of the spoon into the jar so that the two kinds of water will not mix together. 5. Softly place the potato into the jar. Don't drop it. What will happen: The potato will sink - but only halfway! Why: Salt water is heavier than fresh water, so it will stay on the bottom. The fresh water will remain on the top. The potato is heavier than the fresh water, but it is lighter than the salt water. That is why the potato will sink only halfway down.

①属于不珍惜自己宝贵生命的行为           ②折射出宝贵而脆弱的生命需要敬畏

③说明只有轰轰烈烈的人生才值得尊敬   ④彰显了消防员履行职责、温暖社会

某一化石采集队，在甲、乙、丙三个不同的地层内挖掘到许多化石．记录清单如下：甲地层（恐龙蛋，始祖鸟，龟），乙地层（马，象牙，犀牛），丙地层（三叶虫，乌贼，珊瑚）．这些地层依地质年代远近排列应是（　　）