1 . They felt ________ it was high tax and low income ________ contributed to the extreme misery of the working people at the bottom of the ladder.

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

2 . When I try to understand ________ that prevents so many children from being happy, there seem to be three causes.

A．why it is	B．what it does
C．why it does	D．what it is