Criticism and self-criticism is necessary _____ it helps us to correct our mistakes.
| A．by that | B．at that | C．on that | D．in that |
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 |
It was not until near the end of the letter________she mentioned her own plan.
| A．that | B．where | C．why | D．when |
Only by increasing the number of doctors by 50 percent________properly in this hospital.
| A．can be the patients |
| B．can the patients be treated |
| C．the patients can be treated |
| D．treated can be the patients |
At no time________the rules of the game.It was unfair to punish them.
| A．they actually broke | B．do they actually break |
| C．did they actually break | D．they had actually broken |
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 |