The two friends ______on the Internet for three hours, and they would go on till the next morning.
| A．have been chatting | B．had been chatting |
| C．were chatting | D．had chatted |
Unfortunately, I caught a bad cold and ached all _____ last night.
| A．the way | B．over | C．at once | D．the worst |
After his long journey from Australia. Tom returned home, ____.
| A．exhausting | B．exhausted | C．being exhausted | D．having exhausted |
It is partly ______ the summer day is longer that everything has a larger time to warm up.
| A．for | B．that | C．the reason | D．because |
—May I go outside and play for a while, Dad?
—No, you can’t ____ your homework is being done.
| A．until | B．as | C．before | D．the moment |
_____ I heard his voice trembling did I realize what trouble he was in.
| A．Only when | B．Until when | C．No sooner had | D．Hardly had |