. It is necessary for us to learn second language our mother tongue.A. the; besidesB. a;

问题补充：

. It is necessary for us to learn second language our mother tongue.

A. the; besides

B. a; except

C. the; except

D. a; besides

答案：

A. the; besides

B. a; except

C. the; except

(答案→)D. a; besides

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