as: because: because of; since
as: because: because of; since; for的用法区别
as, because, because of, since 和for都有“因为、由于”的意思，它们的用法区别是：
1.as意为“因为、由于”,语气比 because弱，所引导的从句表示的是不言而喻、 为人所知的、显而易见的原因和理由，其从句一般放在主句前。如： As it was late, we came back soon.由于时间很晚了，我们很快就回来了。 As I am free today,, write to you..由于我今天有空，所以给你写信。
2.because意为“因为”,指直接原因，语气最强，常表示必然的因果关系，引 导的原因状语从句是全句意思的重心，它引导的从句一般放在主句的后面
回答以why引起的特殊疑问句，只能用 because.如
Tom didn' t go to school because he was ill汤姆没上学，因为他病了。
Why didn' t John go to the park?约翰为什么没去公园?
Because he had to look after his little sister.
因为他得照看他的小妹妹。
3. because o表示因果关系时，后不能接从句，但能接名词、代词或动名词，此 时它的词性不是连词，而是介词短语。
The football match was cancelled because of rain
由于下雨，足球赛被取消了。 He didn ' t go to Beijing because of that.由于那件事，他没有去北京。 Helen didn't attend the party because of her mother,'s coming. 由于她母亲来了，海伦没有参加聚会。
4. since意为“由于、既然”,所引导的从句表示的是已知事实的理由和一种间 接或附带的原因，语气比 because弱，但比as强，其从句一般位于主句之前
如：
Since it is raining, you'd better take an umbrella with you
既然在下雨，你最好带把雨伞
Since I have no money. I can I buy any food
山于我没钱，所以我不能买食物。
5.for是并列连词，用来附带解释或说明前一句的情况，有时它表示的理由是 推测性的，它所引导的分句只能放在另一分句之后。如
The day breaks. for the birds are singing
天亮了，因为鸟在叫。(表示推测)
He felt no fear. for he was brave e.他很勇敢，毫不畏惧。
【注意】 because, sInce不可与so连用。
请选用as: because: because of; since; for词语的适当形式填空：
1) he can‘t answer the question, you' d better ask someone else
3) The oil must be out, the light went out
4) I haven I seen the film, I can t tell you what I think of it
5) He was absent his sickness
Keys: 1)Since 2)Because 3)for 4)As 5) because ol
小编给大家提供教育资讯，培训问答等内容，为不影响您的学业，来校区前请先电话咨询，免费咨询电话：400-998-6158
