题目内容
用since或for填空:
Sara has been sleeping ________ 9∶00
用since或for填空。
1.I've been playing the piano ________ 9:00.
2.Mary has been running ________ 20 minutes.
3.Sarah has been sleeping ________ 11:00.
4.Dave has been talking on the phone ________ five minutes.
5.Lucy has been studying Chinese ________ he was six years old.
Mary has been running ________ 15 minutes.
She has been walking ________ five hours.