Because of 

as 或 because 都可以表示因为的意思

because of sth.

because ,since ,for ,as 

有2种 because of  ,  thanks  to 

because /because of    
due to
for
As
thanks to
since

because /because of 
due to
for
As
thanks to
since 

because /because of 
due to
for
As
thanks to
since 

because 最常用 后面加句子
because of 后面接词
since 加句子 语气稍弱
for 加句子 
as 加句子
due to 既可加词也可加句子 比较正式的文体用
in that
in respect that 加句子
as a result of 
thanks to 
owing to 
on account of 

当然是because了

so是所以，但是because和so不可以在一个句子中出现

because,  on account of,  as a result of, because of ,都行，要注意是引导句子还是词！

在英语翻译中，解释为“因为”的除了单个词的as、for、since、because等，还有许多短语，例如：due to、thanks to、owing to、because of、what with、on account of、as a result of、by reason of/that等等。中英互译十分灵活，在实际运用上，要注意它们各自的用法和异同。