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

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.

试题答案

B

解析:

本题考查非谓语动词的用法。题意为：一般来说，如果按照说明服这药的话，它不会有副作用。连词when后常接分词做状语，从逻辑上看，take与drug之间明显是被动关系，因此要用过去分词。此处when taken 相当与when it is taken. C项是现在分词的被动式，表示正在进行之意，与题意不符。D项是不定式的被动式，常用做目的状语或定语，在此亦不正确。故答案为B.\