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)