根据句意及汉语提示完成句子。

1. Liverpool was important because of its _____ (工业)  and trade in the 18th century.

2. China does a lot of _____ (贸易) with many countries.

3. The most wonderful _____  (一部分) of last winter  holiday was visiting Harbin.

4. She refused to take on the traditional woman's _____ (角色).