Ответ:

have answered

have you found

I haven't. left

has already gone

have you prepared for the test yet

I have. I have just finished

did, took

haven't walked the dog yet

have already done

hasn't learnt English yet

has been doing homework for two hours

he has already cleaned

has been doing homework since 4 o'clock

has already watered

has already learnt

has just drawn

have already finished