is this research centre _____the foreign guests visited last week.怎么做？

把句子还原成陈述句就是：This research centre is the one (that ) the foreign guests visited last week.
the one做定语从句的先行词，后面的that可以省略，因为先行词在从句中作宾语，可要可不要。如果选A或B的话，句子没有先行词。C的话，the foreign guests visited后就没有宾语了，where等关系副词引导定语从句时后面的从句是完整的句子。
还有一个相区别的句子：Is this the research centre that/which the foreign guests visited last week ? 同理，我们可以吧它还原成陈述句就是：This is the research centre that/which/省略 the foreign guests visited last week.此句中有先行词the reasearch centre,所以用关系代词“that/which/不填”都可以的。
呵呵，希望对你有帮助。

选d。
可以把这个句子调整为肯定句的语序就看出来了，即This research centre is ... the foreign guests visited last week.后面是一个从句，从句前缺少要修饰的宾语，这个宾语应该是This research centre, 因为前边已经出现了，所以用the one 来代替，作This research centre的同位语，同时作为the foreign guests visited last week修饰的中心词。

is this?
this is 吧？