- 试题详情及答案解析
- It has been proved ____ several new kinds of medicine____ a positive effect on the cure of H7N9.
| A．which，has | B．if, has |
| C．that, have | D．what, have |
- 答案：C
- 试题分析：考查名词性从句和主谓一致。本题中的it是形式主语，真正的主语是后面的that引导的主语从句，that在句中不充当任何成分，只是一个引导词而已。主语从句中的主语是several new kinds of medicine谓语动词应该和kinds保持一致，所以使用复数形式have。故C正确。
考点：考查名词性从句和主谓一致