Question

一道英语选择题，请详细解释

Great changes have taken place in that school.It is no longer what it was 20years ago,______poorly equiped.
A.when B.which
答案选A，为什么B不对？which引导非限制定语从句

Answer 1

首先，英语中没有no longer。。。when的固定短语。
is no longer what it was 20years 是表语从句。而when poorly equiped 实为when it was poorly equiped.的省略，是20 years ago 的同位语，而非定语从句或状语从句。
既然不是定语从句，不用which就理所当然了。
请楼主看看这句子：...Two years ago,when I was twenty years ago,I was in American for further education。

Answer 2

when where 也可以引导非限制性从句
先行词是20年前

Answer 3

when (it was)poorly equiped.
______poorly equiped实际上省略了it was。
若加上it was 之后 后面句子成分已完整。用when 做状语 引导状语从句。which引导定语从句时必须充当句子成分，而(it was)poorly equiped.句子完整 故用when

Answer 4

若加上it was 之后 后面句子成分已完整。用when 做状语 引导状语从句。which引导定语从句时必须充当句子成分，而(it was)poorly equiped.句子完整 故用when

Answer 5

如果用which,应改成:"______was poorly equiped.",此处选when引导的是时间状语从句,省略了"it was",即"when it was poorly equiped.",修饰"20years ago".

Answer 6

翻译一下，学校发生了很大的变化，它在也不是20年前的那个学校，那个学校设备很破。
讲的都是学校而不是说的时间