It was with the selfless help of our teacher we realized our dream.A. thatB. whoC. whenD.

问题补充：

It was with the selfless help of our teacher we realized our dream.

A. that

B. who

C. when

D. how

答案：

(答案→)A. that

B. who

C. when

D. how

解析：句意：就是在我们老师的无私的帮助下，我们才实现了我们的梦想。题目中有It was，首先考虑这个句子有可能是强调句式。把It was和横线去掉，发现这个句子仍然语意清楚，结构完整，所以这就是一个强调句，故用that，选A。