1.i borrow a good novel from the libary which i can keep two weeks
2.it was smowing when they got started in the morning.
3.it's a happy to spend the weekends with you
4.he spent 2years learning to draw a pictrue in 5minutes
5.it's polite the give the seat to others on the bus
6.does it matter if i don't attend the meeting tomorrow?
7.i think it happy to help others
8.it's not good to eat so many eggs a day
9.it's dangerous to swim in the river on one's own
10.it's a pity that we missed the football match last Saturday
11.she thought it her obligation to help her classmates learn english
12.they realize that it's useless to explain this to them
参考资料:我相信我的知识水平