defence与defend
一、defence的用法
1. 表示“保卫”或“防御”，注意其后所用介词：后接入侵者或造成危害者用介词 against；若后接被保护者用介词 of。比较：
A thick coat is a good defence against the cold. 一件厚衣服足可以御寒。
People used to build strong walls round their towns as adefence against enemies. 人们从前在城镇四周修筑城墙来抵御敌人。
This fort was once the main defence of the island. 这座堡垒曾经是这个岛上的要主要防御设施。
2. 短语 in defence of, 意为“保卫……”、“为……辨护”。如：
They fought in defence of their country. 他们为保卫祖国而战。
Hundreds gave their lives in defence of freedom. 千百人为了自由献出了自己的生命。
二、defend的用法
1. 表示“保卫”，通常为及物动词，其宾语就是被保卫的对象。如：
They fought to defend their country. 他们为保卫祖国而战斗。
When the dog attacked me, I defended myself with a stick. 那狗向我扑来时，我用棍子自卫。
2. 表示“保卫……免受或抵抗……”，用介词from, against。如：
The wall was built to defend the road from being washedaway by the sea. 建这座堤是为了保护这条路不被海水冲跨。
Our duty is to defend the country against the enemies. 我们的职责是保卫祖国不受敌人侵袭。