根据汉语提示完成英语句子。

1.当飞机起飞的时候, 天正下着大雪。

It _______________________ heavily when the plane____________________. 

2.他们起得很早, 以便能赶上第一班车。

They got up early_____________________ they could ___________________the first bus.

3.孩子们穿上最好的衣服来庆祝春节。

The children ____________________ their best clothes to ___________ the Spring Festival.

4.瞧, 孩子们正在追逐一只小猫。

Look! The children_________________________________ a small cat.

5.我女儿正在写信时, 其他的孩子都在外面玩耍。

My daughter was writing a letter___________ the other children ___________outside.