I had to believe * it was the only thing I could do and that it was the best thing for him.就是这个句子里,第一个believe后面,为什么不加that.(就是在星号的那个地方),因为我看后面好像是用that引出的句子。就是and 后面的那个that.一般什么时候要用that引出从句,什么时候不用呀??