____the bad weather ,the swimming match had been put off .A Because B Thanks to C With the help o,为什么选A 就不可以.那BECAUSE 不能放在句首嘛！

Because 后面要用 of
Because of the bad weather.
A 只有Because 所以是错的。

因为Because后面要加一个of才可以

because 可以放在句首…如果只用because ,那么其必须连一个句子：Because you are a good student ,we choose you .如果不连句子则是because of 的结构…

thanks to 多亏于是对的。
because 是连接词，所以不能用。
because of，due to 后接动名词和名词。而且他们是介词。
连词只可以连接句子。