China became a WTO member _______ December 11th, 2001.

A. on

B. in

C. at

D. of

China became a WTO member ________ December 11^th, 2001.

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China became a WTO member(成为世贸组织的一员)

________ December 11th，2001．

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A. on　　　　　　  B. in　　　　　　  C .at　　　　　　　　  D. of