Generally speaking according to the directions the drug has no side effect.A. when takin

问题补充：

Generally speaking, according to the directions, the drug has no side effect.

A. when taking

B. when taken

C. when to take

D. when to be taken

答案：

A. when taking

(答案→)B. when taken

C. when to take

D. when to be taken

解析：可联系答.案.网客服索取。