Steps must be taken ______this kind of disaster will never happen again.

________ he felt like ________, he reminded himself that he had a family to support.

The science of medicine, _____ progress has been very rapid lately, is perhaps the most important of all the science.

This is the largest clock in the world, _____ the minute hand is six
meters long.

Sarah hopes to become a friend of _____ shares her interests.

He is not such a man _______ would leave his work half done.

The rent is high , ____ the house is quite satisfactory .

.It will not be ________ we can meet again.

. I’ll never trust such a man ______ you described. 

In the final exam of last term, our maths teacher Mr.Wu gave us  ________we all couldn’t work out .