guard balanced by a counter weight

例句：

1. 1. The soldiers stood guard outside the gate.
   士兵们站在门口守护。
2. 2. She is a great protector of her friends.
   她是一个非常好的朋友保护者。
3. 3. He guards his privacy carefully.
   他非常小心地保护自己的隐私。