1. Actions must be taken to make the river clean.
2. The same as other languages in the world, Chinese keeps changing with the times.
3. The more careful you are in the English examination, the less grammar mistakes you will make.
4. They are all those, of who I can beg a favor.
5. Not until one year later, did he get used to his life in high school.
注：
1. clear作为动词一般跟在‘人’后面,clear sth,而不是‘物体地点’（比如题目中的河）,作为副词形容词主要也是修饰‘人’.修饰物体的是‘clean’'tidy'.常见句式有‘are we clear?’(大家都清楚了吗?)‘make those stuff clean’
2. time表示‘时间’,times 表示‘时代’,须有冠词,或者形容词在前面.
4. 额＝.＝个人翻译习惯不一样,of前后都可以的.
5. used to 表示‘过去常常’；'get used to'表示‘习惯’