We 1000 English words since we to learn English.A. learned; beginB. have learning; began

问题补充：

We 1000 English words since we to learn English.

A. learned; begin

B. have learning; began

C. have learn; begun

D. have been learning; began

答案：

A. learned; begin

B. have learning; began

C. have learn; begun

(答案→)D. have been learning; began

解析：since 引导的时间状语从句中，当从句中用since+表示一般过去时时，主句要用现在 完成进行时或现在完成进行时，（动词必须是延续性动词）故选D