二、表示因果关系的并列连词

　　1. for 因为

　　由并列连词for引导的分句常置于句子后部,而且常用逗号与前面的分句隔开。for分句主要是对前一分句补充说明理由或推断原因。for分句不能用来回答why问句。

　　例：I did my best not to show pleasure, but what I was feeling was pure happiness, for my words had the power to make people laugh.

　　2. so 因此

　　可以连接两个句子，中间有时用逗号隔开;也可在so前加and;还可以放在一个句子的句首。

　　例：The shop doesn't open until 11 a.m., so it loses a lot of business.

　　三、表示选择关系的连词or

　　or连接并列成分时，意为“或者，还是”;用于否定句中，意为“也不”，这时不宜用and;还有“否则，要不然”之意，相当于otherwise。

　　例：Would you like a cup of coffee or shall we get down to business right away?