She's my herobecauseshe's one of the best table tennis players in the world,and I love playing table tennis.她是我的英雄，因为她是世界上最好的乒乓球运动员之一，而且我喜爱打丘兵球。
（1）句中because是连词，用来引导原因状语从句。because引导的原因状语从句通常放在主句之后，若需强调则放在主句之前。如：
I did it because they asked me to do it!
我做这件事是因为他们让我做！
Because I was ill,I didn't go to school yesterday.
因为病了，所以昨天我没去上学。
（2）because通常用来回答why提出的问题。如：
— Why didn' t you go to see the film?
—— 你为什么没去看这部电影？
— Because I have seen it.
—— 因为我看过了。
（3）表示“……的原因是……”时，一般要用句型“The reason why…is that…”。如：
The reason why he can't come is that he is tired.
他不能来是因为他累了。
（4）汉语习惯上说“因为……所以……”，但在英语中同一句子里却不能将because与so连用。如：
因为下雨，所以我们待在家里。
[正] Because it was raining,we stayed at home.
[正] It was raining,so we stayed at home.
[误] Because it was raining. so we stayed at home.
我们也可以用since和as引导原因状语从句。如：
Since you are free,you'd better tidy your bedroom.既然你有空，你最好把卧室整理一下。
As you were not there,I left a message.因为你不在那里，所以我留了个信儿。
注意： 和because相比，since和as的语气稍弱。
since意思是“既然；由于，因为”，表示已知的、显然的理由，较正式，多位于句首。如：
Since it is late,I shall go home right now. (由于)时间不早了，我得马上回家。
as和since的用法大体相同，表示附带说明的“双方已知的原因”。如：
As it is raining,you'd better take a taxi.既然在下雨，你最好乘出租车。