帮忙翻译几句英语，别用翻译机，急！

1)This dictionary surely belongs to Wang Lei,beacause his name is on it.

2)Lao She is the favorite writer of our Chinese teacher.

3)It's likely that I left my french book in the classroom.

4)This examination is very important for us,beacause it covers thirty percent of the final evaluation.

5)On my way home yesterday, I saw a policeman was on heel of a thief.

6)I have missed the first bus, so I'm worried about the appointment with my friend.

7)There are many species in nature,and they are all vital for human's existence and development.