- 试题详情及答案解析
- I won't tell the student the answer to the math problem until he on it for more than an hour.
| A．has been working | B．will have worked |
| C．will have been working | D．had worked |
- 答案：A
- 试题分析：考查动词时态。句意：我直到他已经做这道数学题超过一个小时才告诉学生们数学答案。根据“for more than an horn。”知选用现在完成进行时态。
考点 : 考查动词时态