__________ he is old, the old man still insists on studying at a night school.
| A．If | B．Although | C．When | D．Because |
You have to pass a driving test_____ you can get a license
A before B until C when D since
What impresses me most is ______ he appears in front of others, he wears a sincere and charming smile．
A．which B．that C．where D that whenever
____ difficulties we meet, we can work them out.
| A．Whatever | B．However | C．Wherever | D．Whenever |
The meeting was expected to start at 9 o'clock but the manager didn't turn up ______ twenty minutes later.
| A．before | B．until | C．after | D．since |
Although he was in poor health, Robert succeeded ______ other more famous engineers failed.
| A．which | B．that | C．what | D．where |