根据汉语提示，将英语句子补充完整。
1. 这张桌子太重我搬不动。
The desk is _____ _____ for me _____ _____.
2. 他们昨天在晚会上玩得很开心.、。
They _____ _____ _____ _____ at the party yesterday.
3. 莫扎特4岁时开始写曲子。
Mozart started _____ _____ when he was four years old.
4. 当我出去的时候我看见他们在踢足球。
I _____ _____ _____ football when I went out.
5.The boy began to go to school _____ _____ _____ _____. (在他7岁时)