问题补充：
He said that he would write to us but so far we from him.
A. didn’t hear
B. haven’t heard
C. shouldn’t have heard
D. hadn’t heard
答案：
A. didn’t hear
(答案→)B. haven’t heard
C. shouldn’t have heard
D. hadn’t heard
解析：考查时态。根据题中so far 到目前为止，可知应用现在完成时态，句意：他说他会给我们写信但是到现在为止我们还没有收到他的来信。所以选B。
