英语 (29 10:36:26)It ______ Mike and Mary who helped the old man several days ago.A．was    B．are    C．were    D．had been_______ four years since I left my home town.A．It was 

英语 (29 10:36:26)It ______ Mike and Mary who helped the old man several days ago.A．was    B．are    C．were    D．had been_______ four years since I left my home town.A．It was 
英语 (29 10:36:26)
It ______ Mike and Mary who helped the old man several days ago.
A．was    
B．are    
C．were    
D．had been
_______ four years since I left my home town.
A．It was   
B．There was   
C．There is   
D．It is

英语 (29 10:36:26)It ______ Mike and Mary who helped the old man several days ago.A．was    B．are    C．were    D．had been_______ four years since I left my home town.A．It was 
C mary and mike是两个人所以用过去时复数形式.
A it表时间的时候是单数.

1、A ，这是强调句型，结构为It is/was……that/who……
2、D

1、选A。It作主语，当然谓语是单数；后面是helped，当然谓语是过去时。
2、选D。说的是过去到现在有多长时间，不能用过去时；而谈论时间不能用there be句型，要用无人称代词It。

1 it was 强调句式 it is/was ...that/who
2 it is 固定句式:it is... since+过去时