It was not until dark _____he found _____he thought was the correct way to solve the problem.   

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

It was not until dark _______ he found _______ he thought was the correct way to solve the problem.?

A. that; what B. that; that　?

C. when; what D. when; that?

It was not until dark _____ he found _____ he thought was the correct way to solve the problem．

It was not until dark __________ he found __________he thought was the correct way to solve the problem．

It was not until dark _____ he found _____ he thought was the correct way to solve the problem.

It was not until dark         he found         he thought was the correct way to solve the problem.

It was not until dark _____he found _____he thought was the correct way to solve the problem.

A.that; what??????? B.that ; that?????? C.when; that?????? D.when ;what

 It was not until dark ______ he found ______ he thought was the correct way to solve the problem.

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

 It was not until dark         he found         he thought was the correct way to solve the problem.

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

It was not until dark _____ he found _____ he thought was the correct way to solve the problem.

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