generally speaking,when(taken)according to the instructions,the drug has no side effect

题目

generally speaking,when(taken)according to the instructions,the drug has no side effect
为什么不能taking to take to be taken

答案

　　when后面所跟的动词的主语与主句主语一致.　　when done:表示动作完成后发生主句描绘的情形,与主句主语是被动的关系　　When asked by the police,he said that he remembered nothing .　　when being done:与...