高考英语词汇：act　as与act　for

1. act as (临时)担任，充当，起……的作用。如：
　　A trained dog can act as a guide to a blind person. 经过训练的狗可以担任盲人的向导。
　　表示担任独一无二的职务，其前通常不用冠词。如：
　　He acted as manager in my absence. 我不在时他担任经理。
　　I don’t understand their language; you’ll have to act as
　　interpreter. 我不懂他们的语言，你得当翻译了。
　　2. act for 代理(某人职务)，代为(处理某事)。如：
　　Please act for me during my absence. 我不在时请代理我处理事务。
　　I acted for our captain while he was in hospital. 我们队长住院时由我代理他。