-------What is it made Carl determined to give up smoking?
-------Watching how his father died in pain from lung cancer.
| A．which | B．how | C．who | D．that |
____ the problem of method is solved, talking about the task is useless.
| A．Until | B．Since | C．After | D．Unless |
Where have you been ____ you left home?
| A．before | B．as | C．since | D．when |
____ you told me, I had heard nothing of what happened.
| A．Till | B．Until | C．After | D．Since |
He ran off____ I could stop him.
| A．before | B．after | C．since | D．when |
We should pay attention ____ to industry ____ to agriculture.
| A．either, or | B．neither, nor | C．not, but | D．both, and |