It was never clear ________ the man hadn't reported the accident sooner.(2011·江苏)
A．that B．how C．when D．why
(2012·天津)It doesn't matter ________ you turn right or left at the crossing—both roads lead to the park.
A．whether B．how C．if D．when
________ was most important to her，she told me，was her family.
A．It B．This C．What D．As
It suddenly occurred to him ________ he had left his keys in the office.(2012·江西)
A．whether B．where C．which D．that
Have you noticed the problem ________ he is now in low spirits？________ come?
A．where；What B．that；How
C．in which；For D．what；As
(2011·辽宁，32)When the news came ________ the war broke out，he decided，to serve in the army.
A．since B．which C．that D．because
