根据汉语提示完成句子。

1.We won't go to the park______________(如果天下雨).

2. It was already dark____________(我们到那儿的时候).

3.____________(如果彼得不努力学习), he won't be able to pass the exam.

4.______________(他一痊愈), he went back to work.

5.______________(如果她妈妈五点前不同家),she will do the cooking,