例：It is generally considered unwise to give a child he or she wants.
A．however B．whatever C．whichever D．whenever
答案是B。
21．—I'm terribly sorry, Lucy．I've left your notebook at home．
—_____? I reminded you last night．
A．So what B．Why not C．How come D．What if
22．—You've finally figured out the puzzle!
—Yeah, in a complex way, _____．
A．too B．though C．either D．yet
