按点检时间间隔和检查内容不同，点检可分为三类，它们是()。

A.移动点检

B.固定点检

C.日常点检

D.专项点检

E.定期点检

Questions 1-4

According to the talk, what is a plateau？（）

A．A temporary condition where you don’t feel any progress in learning.

B．A flat and smooth spot in your study where you make fewer mistakes.

C．A long-term struggle which does not bring you any tangible rewards.

D．An educational research on language learning that is unusual and advanced.