At times the balance in nature is ______ , resulting in a number of possibly unforeseen effects.
| A．troubled | B．confused | C．disturbed | D．puzzled |
The novels written by the author sell best, but five years ago no one could have imagined how great a role he __________ in the literary world.
| A．was playing | B．was to play |
| C．had played | D．played |
—__________ you __________ the editor at the airport?
—No, he __________ away before my arrival.
| A．Have ； met ； has driven |
| B．Had ； met ； was driven |
| C．Did；meet；had been driven |
| D．Have ； met ； had driven |
He will stop showing off, if no notice __________ of him.
| A．is taken | B．will be taken |
| C．takes | D．has taken |
—Alice, why didn't you come yesterday?
—I __________，but I had an unexpected visitor.
| A．had | B．would |
| C．was going to | D．did |
I don't believe you've already finished reading the book—I __________ it to you this morning ！
| A．would lend | B．was lending |
| C．had lent | D．lent |