21, a
22, b
23, a
24, a
25, b
26, b
27, c
28, a
29, c
30, b
II,
1. We wish it didn't rain today
2. She wishes she joined in the trip with her classmates
3. He wishes he got good mark this semester
4. She wishes she had enough time to do the test
5. I wish it weren't cold and windy
6. She wishes she didn't miss the bus to school
7. I wish I could hear that strange noise
8. They wish they did something for their mini-project
9. They wish they would go fishing this weekend