Choose the correct verb form for each space. 1 1. This

Choose the correct verb form for each space. 1
1. This is the first time I have done/do/did this exam.
2. When I left home this morning it was raining.
3. By the time you arrived at the party, all of the interesting people went/have gone/ had gone home!
4. Tomorrow I think it will rain.
5. John didnt like his job at all and so decided resign/resigning/to resign.
6. I saw your mother while I have walked/was walking/am walking to work .
7. I try/have tried/have been trying to understand this grammar for hours, but I just cant!
8. Your final exam might/would/can be difficult, but I'm sure you'll pass!
9. I couldnt come to the party because I did/must do/had to do my homework.
10. You couldn't have/might have/could have chosen a better person for the job. She was perfect!
11. In Britain you mustn't/don't have to/need do military service.
12. Weve been friends for a long time. We know/knew/have known each other since we were young.
13. If the teachers were/teach/are better, the students would learn more.
14. Why aren't the students told/didn't the students told/weren't the students told that the exam format had been changed?
15. As part of the preparations for this years World Cup, a new stadium is being built/is building/will build.