One won't learn a foreign language well he studies hard.A.ifB.if notC.untilD.unl
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One won't learn a foreign language well ________ he studies hard.
A.if
B.if not
C.until
D.unless
试题答案
D
One won't learn a foreign language well ________ he studies hard.
A.if
B.if not
C.until
D.unless
D