A housing bubble is an economic situation _____ occurs when house prices rise much too fast.
| A．which | B．where | C．what | D．why |
—Who has taken my pen away?
—__________. He was here a moment ago.
| A．It must be Li Ping | B．It is Li Ping take |
| C．Li Ping is | D．Li Ping must take |
Besides Tom, ________ Crosettes have two other sons, __________ of whom are all interested in making model planes.
| A．不填; two | B．不填; the two |
| C．the, three | D．the, the three |
Nobody noticed the thief slip into the house because the lights happened to__________.
| A．put up | B．give in | C．be turned on | D．go out |
The news about the terrible flood there greatly discouraged __________ there for a sightseeing.
| A．us from going | B．us to go | C．our going | D．our to go |
He's unlucky,and he's always suffering____________ luck one after another.
| A．a sick | B．an ill | C．sick | D．ill |