Question

In my opinion, all Mr. White ___ good to his students in his class at present.

In my opinion, all Mr. White ___ good to his students in his class at present. He is very strict in their study.
A. does does does B. does do do
C. does does do D. did do does
答案是B，求分析，第一个我觉得是did，指Mr. White所做过的啊

Answer 1

答案C.不是第二个，楼主。

根据句子结构可知，Mr Li does是定语从句，修饰先行词语all; 第二个does是强调，意为的确，第三个do是do good to对……有好处的词组
用 does,是因为主语all 表示事情，看做单数，所以用does来强调，那么后面的动词必须用原形；所以后面出现了do。
I do know him.我的确认识他。

句意为，在我看来，李先生所有做的事情的确对他班级的学生是有好处的，他在学习上对他们非常严格。

Answer 2

我翻了一下我的牛津字典。
简单现在时用于：
1表示长久的状况或永远的事实。
he lives in a factory
does he work in the factory？
2表示经常发生的事
she leaves for school for 8 o'clock
we don't often go out for a meal
what time do you catch the bus
简单过去时：
1表示过去进行的动作
he got up，paid the bill and left
i didnt read the letter，i just gave it to Lee
（note）通常提及过去的具体时间
did you speak to Amy yesterday？
2表示持续一段时间，但是现在已经结束
i went to school in Scotland
我曾在苏格兰上学
did she deally work there for ten years?
3表示过去经常发生的事
i often played tennis with her。she always won
they never went to cinema when they lived in the country
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我觉得这里选择C是因为有at present。现在