_______ is well known _______ Hong Kong returned to China on July 1st, 1997.
| A．It, that | B．As, / |
| C．As, as | D．It, which |
.________ gas leaks and similar accidents should occur, some responsible persons should regularly inspect all the laboratories.
| A．Unless | B．In case | C．Provided | D．Until |
. ________ in one leg, he never had a chance to get a job.
| A．Weak and lame | B．He was weak and lame |
| C．Though weak and lame | D．Weak and lame as he was |
. The production of television commercials must be professional ________ they aim at promoting good service, or public education.
| A．when | B．no matter | C．if | D．whether |
. The prices have been going up, so that the richer you get, the less rich you are than ________ you think you ought to be.
| A．that | B．/ | C．what | D．which |
定语从句及其关系代词与副词
. Jane came to settle down in New York in , ________, some time later, she became a middle school teacher.
| A．where | B．when | C．at which | D．that |