3.We were just_ calling you up...

题目

3.We were just_ calling you up...
3.We were just_ calling you up_you came in.
A.about,when
B.on the point of ,while
C,on the point of ,when
D.on the point of ,as
正确答案是C,我选了D,想问问为什么这样选

答案

答案是C
本题考查固定句型be about to do .when
be on the point of doing ...when
be just doing ...when
had just done...when
表示某人刚要、正要做某事,就在那时突然...,本句型中when是并列连词,相当于at this/ that time
本题意思是：我刚要打电话给你,你正好来了.