1 . Can you explain ________ the sun goes down in the west?

A．why is it that

B．why it is that

C．how it is that

D．how is it that

2 . It was the belief _____ Alex Haley could find his root in Africa ____ made him decide to go to Zambia.

A．/; which

B．which; that

C．that; which

D．that; that