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.