As we all know, ______ knowledge comes from _______ practice.
| A．the; the | B．a; a | C．the ;× | D．×; × |
It was with the help of the local guide________the mountain climber was rescued.
| A．who | B．that |
| C．when | D．how |
It was not until near the end of the letter ________ she mentioned her own plan.
| A．that | B．where |
| C．why | D．when |
It was only after he had read the papers ________Mr.Gross realized the task before him was extremely difficult to complete.
| A．when | B．that |
| C．which | D．what |
Only when he apologizes for his rudeness________to him again.
| A．I will speak | B．will I speak |
| C．do I speak | D．I speak |
Not once________to Michael that he could one day become a top student in his class.
| A．occurred it | B．it did occur |
| C．it occurred | D．did it occur |