Ответ:
1) The children are in the yard. They have been playing hide-and-seek since breakfast time.
2) Barbara has been doing her make-up for half an hour but hasn't finished it yet.
3) Nice to meet you. I haven't seen you for a long time.
4) We have heard nothing of him for two years (без двойного отриц.)
5) She is a well-known artist. She has been drawing since her childhood
6) She has always liked cats. And now she has three at home.
7) Is Tom still ill? No. He has just recovered
8) Have you sent them the contract yet?
9) I have been translating this story since morning, but still can't understand some sentences.
10) Ben hasn't been doing his homework all this time. He has been playing computer games.
11) You look upset. What has happened to you?
12) "Sorry, I'm late" - "That's all right. I have not been waiting long."
Объяснение: