Fill in the blank

5. thank you for your help. i..... able to finish my thesis without it.
6. ...the government fall, the stock market will crash.
7. if only i ...... a motorcycle instead of a car. i wouldn't have to spend so much on petrol.

-> giải thích giùm mìnk các câu này và cách lm ntn vs ạ 

mìnk cần gấp ạ!!!