Question

3. Is this factory ________ some foreign friends visited last Friday?

3. Is this factory ________ some foreign friends visited last Friday?　　A. that B. where C. which D. the one为什么选D.

Answer 1

3. Is this factory ________ some foreign friends visited last Friday?　　
A. that B. where C. which D. the one
选D.
因为把Is this factory the one some foreign friends visited last Friday?改成陈述句，就一目了然了：
This factory is the one (that/ which) some foreign friends visited last Friday.

Answer 2

你把句子改成陈述语序就理解了。
This is factory ________ some foreign friends visited last Friday.

读一下是不是感觉factory前面少了定冠词the？然后你就很轻松可以选出D了。
the one = the factory。

Answer 3

你把它转换成陈述句 应该就是 this is the factory——some foreign friends visited last Friday。然后你试一下这几个词，显然应该是用the one代指the factory
that which 一般用于从句中 个人认为这个不是从句 就是定语后置的一些用法

Answer 4

这里有一层特指的意思，，factory 究竟是哪一个factory。。the one 对factory 进行了限定