Up to now, no one has come up with a（n） explanation of why dinosaurs died out, and it remains a mystery．
| A．astonishing | B．amusing | C．convincing | D．puzzling |
Mr. Thompson, without _________timely help finishing the task would have been out of the question, fell ill last week.
| A．his | B．whom | C．who | D．whose |
Being hungry, I was in search of cake or fruit in the fridge, but found _______.
| A．everything | B．none | C．anything | D．something. |
Considering all that she had _______, she was really an amazingly cheerful woman.
| A．gone for | B．gone through | C．gone in for | D．gone about |
How long do you think ____ the car factory launches a new model?
| A．will it be until | B．will it be when | C．it will be before | D．it will be that |
Having lived in China for 8 years, Helen has a good ______ of both English and Chinese．
| A．program | B．guidance | C．command | D．ability |