— Have you found your English book? — I am not sure ____ I could have left it.
A.whether
B.what
C.when
D.where
参考答案:
The clever boy made a hole in the wall, _______ he could see..
The clever boy made a hole in the wall, _______ he could see _____ was going on inside house. A.which; whatB.through which; whatC.through that; whatD.what; that
Asia has achieved more in controlling the bird flu than Euro..
Asia has achieved more in controlling the bird flu than Europe in the past few years, _______ the number of people infected with the virus is going up sharply.A.whenB.thatC.so thatD.where
Many young people in the West are expected to leave __ could..
Many young people in the West are expected to leave __ could be life' s most important decision -- marriage -- almost entirely up to luck.A.asB.thatC.whichD.what