1) Ron washed his car yesterday.
2) Children are playing football in the yard now.
3) We usually go to the swimming pool three times a week.
4) Jane hasn't cleaned her room yet.
1. a) washed
2. b) are playing
3. b) go
4. a) hasn't cleaned
В первом a) потому что это Past Simple, во втором Present Continuous, в третьем Present Simple и в четвертом Past Perfect