---Bob has gone to California.
---Oh, can you tell me when he _________?（2011北京卷32）
| A．has left |
| B．left |
| C．is leaving |
| D．would leaving |
_________ the right kind of training , these teenage soccer players may one day grew the international stars．
| A．Giving | B．Having given | C．To give | D．Given |
Please do me a favor — ______ my friend Mr．Smith to Youth Theater at 7:30 tonight．
| A．to invite | B．inviting | C．invite | D．invited |
Nowadays people sometimes separate their waste to make it easier for it ______．
| A．reusing | B．reused | C．reuses | D．to be reused |
At the age of 29, Dave was a worker, ______ in a small apartment near Boston and ______ what to do about his future．
| A．living; wondering | B．lived; wondering |
| C．lived; wondered | D．living; wondered |
When he ______ the door, he found his keys were nowhere．
| A．would open | B．opened | C．had opened | D．was to open |