It was Asimov was eleven years old his talent for writing became obvious.
| A．that, when | B．When, that |
| C．when, when | D．when, which |
When the bell rang announcing the end of class, students came out _____.
| A．by twos and threes | B．by two and three |
| C．by two and three | D．by twos or threes |
His father has made a _____ bench for him.
| A．four legged | B．four-leg | C．four-legged | D．four legs |
More than _____ of the workers _____ from Paris.
| A．ten percent, is | B．ten percent, are |
| C．three times, was | D．percent ten, comes |
Despite the wonderful acting and well-developed plot the _____ movie could not hold our attention.
| A．three-hours | B．three-hour | C．three-hours' | D．three-hour's |
We elected him _____ headmaster of the school for _____ second time.
| A．/, a | B．the, a | C．the, / | D．/, / |