16. I returned home with some roses and only then __________ find my favorite vase missing.
| A．I did | B．did I | C．do I | D．I do |
As is well known, the brain performs a very important _______, which controls the nerve system of the body.
| A．motion | B．action | C．function | D．fact |
—Jack Brown is very clever and he studies hard as well.
—No ________ he comes out first in the exams.
| A．answer | B．question | C．wonder | D．problem |
—Paul has gone abroad to try his luck.
—In my _______, his decision is not wise.
| A．word | B．view | C．sight | D．way |
The financial crisis has put the world economy in a difficult _________.
| A．occasion | B．condition | C．evaluation | D．situation |
Most air pollution is caused by the burning of ____ like coal, gas and oil.
| A．fuels | B．articles | C．goods | D．products |