VIII.
1.If we try to recycle things, we will save natural resources
2.Mr. tan has begun to work as a weatherman since last year
IX.
1. The book which I gave him yesterday is very interesting
2.You will not pass the coming exam unless you work hard 
4. Nobody in the factory works more careful than Mr. Jones
VIII.
1. We spent five hours getting to London
2. I suggest that we should speak English in class
IX.
1.Our children like watching cartoon films on TV
2.My mother asked us not to go out in the evening 

=>
VIII/
1. If we try to recycle things, we will save natural resources.
2. Mr.Tan has worked as a weatherman since last year.
IX/
1. The book (which) I gave him yesterday is very interesting.
2. You won't pass the coming exam unless you work hard.

4. Nobody in the factory can work more carefully than Mr.Jones./ Nobody in the factory can work as carefully as Mr.Jones.
VIII/
1. We spent five hours getting to London.
2. I suggest speaking English in class./I suggest that we should speak English in class.
IX/
1. Our children like watching cartoon films on TV.
2. My mother asked us not to go out in the evening.