问题
选择题
－Hello, Mary! This is John. You must know why I _________ you.
－Oh, hello, John! I've waited for this call since last month.
A．called
B．am calling
C．was calling
D．have called
答案
答案：B
考查动词时态的用法。两人正在电话通话，而且后面提到的电话也是这个电话，排除了其他时间的电话。所以“我给你打电话”用现在进行时。