Question

It is the first time_I have come to your city. A that B which C what D when

Answer 1

选 that，that后面的句子是作为定语从句修饰time的，先行词time指物，关系代词用that和which。但time有序数词修饰，则只能用that
指物时，只能用that而不能用which的特殊情况是：
①先行词为不定代词,all,much,something,everything,anything,nothing,none,the one等,
②先行词被only, any, few, little, no, just, very, one of等词修饰时。
③先行词是序数词时或被序数词修饰时。
④先行词是最高级或被最高级修饰时。
⑤先行词既有人又有物，用which和who都不适合，这时宜用that.
⑥被修饰词为数词时.
⑦如果有两个从句，其中一个关系代词已用which ,另一个关系代词宜用that，以避免语言
的单调或重复。
⑧疑问词是who或which，关系代词宜用that，以避免重复。
⑩被修饰成分为表语时，或者关系代词本身是定语从句的表语时,该关系代词宜用that .
⑨主句是There be 结构，修饰其主句的定语从句宜用that 作关系代词.
希望以上解答能帮助你理解！

Answer 2

选A.that.因为先行词是序数词，在宾从中要用that.

Answer 3

A 先行词有序数词 关系代词要用that

Answer 4

选A。
关于完成时的两种搭配：
①序数词+完成时
e.g. This is the tenth cup of coffee that I've drunk this night.
②最高级+完成时
e.g. He is the cockiest guy that I've seen in my life.

Answer 5

选D吧.. 因为定语从句里主谓宾都有了..