His failing in the exam ________ us because he was always an outstanding student.
| A．pleased | B．astonished | C．excited | D．frightened |
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 |
In April, 2009, President Hu inspected the warships in Qingdao,____the 60th anniversary of the founding of the PLA Navy．
| A．marking | B．marked | C．having marked | D．being marked |