Some scientists recommend that nano particles be treated as new chemicals with separate safety tests and clear labelling.选自剑桥雅思10T4 S4.
请问这里为何是be treated 而不是is treated 或是 are treated?
be treated 前面省略了 should。这与动词recommend 有关，即recommend 后面接宾语从句时，宾语从句的谓语动词一般用 should + 动词原形（其中的 should 也可以省略，假如省略了 should，就只剩下原形；若是被动语态，省略 should 就只剩下 be + 过去分词）。又如：
I recommend that he buy this book. 我建议他买这本书。
The committee recommended that the chief executive be dismissed. 委员会建议罢免总经理。
I’m not the person to recommend how the job be done. 我不是能为做此事出主意的人。
Doctors recommended that the drug be taken off the market. 大夫建议市面上应停止供应该类药物。
