We all want to be healthy children, -- we should change our bad habits. A if B because C but D so

误：Because it was raining,so we stayed at home.
正：Because it was raining,we stayed at home.
正：It was raining,so we stayed at home.
能看出问题了吗?选D因为不用because
because和so不能再句子中同时出现,并且用because可以,但要放句首!
但问题是现在句首没怎么办,那么就用so!因为所以!