可通过观察水上部分的明显变化而初步分析判断水下是否有坍塌现象。
参考答案：对
根据括号里所给的汉语写出英语单词。
1. The music is sweet, she often _______(分享)it with me.
2. The activities of learning from Lei feng in our school is very _____(受欢迎)with students.
3. He can speak English________(更好)than I.
4. If I am wrong, I will not mind saying ______(道歉) to him.
5. He bought a useful ________ (书)as present for my birthday yesterday.
人民调解协议在（）日内可以申请申请司法确认和强制执行。
A、15日
B、30日
C、20日
D、10日
hday yesterday.