阅读下面短文，在空白处填入一个适当的词，或填入括号中所给单词的正确形式。

    In Africa, when the antelope（羚羊）wakes up every morning, the first thing ____ comes into his mind is, “I must be able to run ____ (fast) than the fastest lion,____ I will be killed by a lion.” And at just the same time, the lion____ (wake) out of his dream, and the first thingflashing into his mind is: “I must be able to catch up ____ the slowest a ntelope, otherwise I will starve to____ (dead).” So almost at the same moment____ the antelope and the lion jump to their feet, and start____ (run) toward the rising sun.

    Such is life whether you are an antelope ____ a lion, you ought to dash forward without hesitation when the sun ____ (rise).

新中国成立后，中国人民从此过上了幸福安宁的生活。为什么在第一届中国人民政治协商会议上还要将曾经激发中华民族英勇战斗的《义勇军进行曲》定为国歌呢？为什么还要时时唱起“中华民族到了最危险的时候”呢？用一个成语来表达是（    ）

从“人-----从------众”和“森-----林-----木”的变化中主要反映的问题分别有                    （     ） 

下列有关生态系统的叙述中，正确的是（    ）

如果${\log }_3^m+{\log }_3^n=4$，那么$m+n$的最小值是（   ）