It has not been decided ________ they will leave for New York．

A．when

B．why

C．that

D．what

Is ________ true that the famous scientist will give us a lecture next week?

A．that

B．it

C．his

D．he

________ has passed the test will get a prize．

A．Whoever

B．No matter who

C．Whomever

D．Who

________ he always serves the people very well is known．

A．What

B．That

C．Which

D．Who

________ caused the accident is still a complete mystery．

A．What

B．That

C．How

D．Where

It is widely ________ that smoking can cause cancer．

A．believed

B．think

C．say

D．hoped

________ appeared to me that he enjoyed the food very much．

A．What

B．It

C．All that

D．That

________ all the inventions have in common is ________ they have succeeded．

A．What; what

B．That; that

C．What; that

D．That; what

________ he will go to work in a mountain village surprises all of us．

A．What

B．That

C．Whether

D．If

________ more countries can use natural energy in the future remains to be seen．

A．Whether

B．This

C．Who

D．If