关于英语强调句的题，，解释的详细些，越详细越好，谢谢

Question

1.It was six o’clock in the morning _ they arrived at the small village.
A. that B. which
C. when D. where

2。It was at six o’clock in the morning _ they arrived at the small village.
A. that B. which
C. when D. where
还有一个。。
3.It was in the lab __ was taken care of by
Jack __ they did the experiment.
A. which, that B. where, that
C. where, where D. /, that

Answer 1

首先，强调句有两种，一是强调动词的，二是强调主语,状语，宾语等其他的。
一的句式是在原句动词根据时态加上do或did或does，例如：
I like watch TV.强调就是：I do like watch TV.
He likes eating.——He does like eating.
I ate the apple.——I did eat the apple.
这里需要注意加上do，did或does后动词要用原形。

二的句式就是 It is......that.......
把句中要强调的部分放在前面的上省略号，后面照抄即可，所以这种强调句的突出特点就是你把“It is that”去掉后整个句子仍然正确，如果去掉后不对，就不是省略句。
第一题，假设是省略句，把it was 和横线（that）去掉后：six'o clock in the moring.......显然不对，要加at才成立，所以1不是省略句而是时间状语从句，所以填when.
第二题用同样方法可知它是省略句，所以选A
第三题是强调句和名词性从句的复合句，第一条横线填which充当从句宾语（因为从句was taken of by Jack没有表明Jack take care of 的是什么，所以缺宾语），后面填that后形成强调。

Answer 2

强调句就是 it is .......that 中间加的是被强调的部分，除了谓语动词都能强调。
判断一句话是否是强调句， it is .......that 去掉后还是完整的句子就是强调句，反之，则不是。

由此判断：1 C when 引导的时间状语从句
2。A 强调句
3 A 强调句 去掉it was that 来看
they did the experiment （in the lab which was taken care of by jack。)括号里的地点是被强调的地方，其中被强调的地方lab后还接了个定语从句 ，which代替先行词lab在定语从句中做主语