That was the only gate _____ we could rush out and save those _____ were in great danger.

  A. that; which               B. which; who        

  C. through which; who        D. at which; who

 It is exactly ______he often fails in the exam ______ makes his parents worried about him.

A. what; that         B. that; which          C. that; that           D. what; what

Shackleton kept his promise ____he would return to Elephant Island ____the crew had been left.

A. which; that    B. that; which   C. what; where    D. that; where

It is in Qingdao ______ you are going to pay a visit to ______ this kind of washing machine is  produced.

I shall never forget the day       Shen Zhou V was launched ,         has a great effect on my life .

A．when , which       B．that , which   C．which ,that    D．when , that