用适当的连词或连接词将下列句子(3)

问题描述:

用适当的连词或连接词将下列句子(3)
It was very hot yesterday.I couldn't fall asleep.

正确答案应该是:
Because it was very hot yesterday,I couldn't fall asllep.

It was very hot yesterday,so I couldn't fall asllep.

It was very hot yesterday so that I couldn’t fall asleep.
昨天太热了,以至于我无法入睡