1.The teacher asked him ________ .
A.whether she was right or not B.which to choose answer C.where did he live D.who to be ill (我知道这道题选A，但是想问一下为什么不能选D )
2.have trouble 后面是加 doing 还是to do？还是其他的。
3.Do you have any problems________ （solve）it？（是solving还是to solve。为什么。）
4.It's a long time since we _______（meet）last time.
（按道理说有since应该是现在完成时，但是这里填have met好像有点问题，所以不知道到底是have met还是met、请解释下。）
5._____（talk）to your friends when feeling sad and _______（share）your worries with them.（我觉得两个都应该是ing形式，但是我有个同学是两个都是原形，所以问一下到底是什么。顺便说一下为什么。）
6.It's better to stay at home than_________（go）swimming.(是to go还是go。顺便说一下为什么不是另外一个。)
7.另外，protection是否可数？就是“get good ________（保护）”是填protection还是protections？
谢谢。如果回答的好的话。我在加分。
资深英语教师在线指导！
1.The teacher asked him ________ .
A.whether she was right or not B.which to choose answer C.where did he live D.who to be ill
这里必须填“名词性结构”。 名词性从句必须是陈述语序，故C错。
"Wh+ to do" 是名词性结构，B项中存在错误，D项从语法角度是可以的，但语义有问题。“老师问他谁将会生病。”
2.在.....方面有困难, 介词in可省略
have trouble / difficulty (in) doing sth.
have trouble / difficulty with sth.
3.Do you have any problems________ （solve）it？
在.....方面有困难, 介词in可省略
have problems (in) doing sth.
have problems with sth.
4.It's a long time since we _______（meet）last time.
It is + 时间段 + since .... = It has been + 时间段 + since .... 这是用一般现在时代替现在进行时。
主句是现在时间，since分句中只能用一般过去时。
又如： It's ages since I enjoyed myself so much. 好久没有这么开心过了。
It's 5 years since I lived in Beijing. 我离开北京五年了。
5._____（talk）to your friends when feeling sad and _______（share）your worries with them.
这两处都是祈使句。若用ing，就不是句子了，而是一个并列的短语。
6.It's better to stay at home than_________（go）swimming
在 it's better to do sth than...., would rather do sth than ...., would do sth rather than ...., prefer to do sth than ....这些句型中，than 后接不定式。这是规定，没道理可讲，记住就行了。
7。protection通常不可数。 但表示“保护者，保护物”时，是可数的，但只用单数形式。