Correct the mistake in the following sentences

Exercise 4: Correct the mistake in the following sentences.
1. When I walk past the park, I saw some children play football.
A
B
C
D
2. After John eaten dinner, he wrote several letters and went to bed.
A
B
C
D
3. What did you do at 9 o'clock last night? I was phoning you but nobody answered
A
B
C
D
4. When I arrived at the station, the train has already left.
A
B C
D
5. Ann and Susan have known each other during they were at school.
C
D
A
B
6. She has disappeared three days ago, and they are still looking for her now.
A
B
с
D
7. After Mrs. Wang had returned to her house from work, she was cooking dinner.
A
B
C
D
8. It's the first time I saw this film.
B C
A
D
9. After he graduates from university, he joined the army.
A
B
C
D
10. Up to now, there have been no woman being chosen the US president.
B C
A
D