1. He______more than 5000 English words when he entered the university at the age of 15.
A. has learned B. would have learned C. learned D. had learned
【注】用于某些特殊句型：no sooner''''''than ， hardly''''''when ， scarcely''''''before等。如：
We had no sooner set out than a thunderstorm broke.
He had hai'dly arrived when it began to snow. 他一到，天就下起雪来了 。（主句谓语要用过去完成时）
Scarcely had I arrived at the station before the train left.
2.When the old man______to walk back to his house ， the sun______itself behind the mountain.
A. started;had already hidden B. had started ；had already hidden
C. had started；was hiding D. was starting ；hid
3.Father______for London on business upon my arrival,so I didn't see him.
A. has left B. left C. was leaving D. had left
4.The policeman 's attention was suddenly caught by a small box which______placed under the Minister 's car.
A. has been B. was being C. had been D. would be
5." Hurry up ！ Alice and Sue are waiting for you at the school gate. " " Oh ！ I______thought they without me."
A. wen B. are going C. have gone D. had gone