祸害的英文：
disaster; harm
damage; harm; wreck

参考例句：

They little think that mischief is at hand.
他们想不到祸害就在前面

foxes can be a curse to farmers.
狐狸可给农民带来祸害。

Mischief comes by pounds and goes away by ounces
祸害易来难去。

Drug addiction is a dangerous canker in society.
吸毒成瘾是腐蚀社会的一大祸害。

We should check erroneous ideas at the outset to nip an evil in the bud.
我们应该防微杜渐，把祸害消灭在萌芽之中。

Drug addiction is a dangerous canker in society
吸毒成瘾是腐蚀社会的一大祸害.

After the scourge of flood usually comes the scourge of disease.
洪水的蹂躏之后常常带来疾病的祸害。

Politically useful,sound,disastrous,etc ideas
政治上有好处、没问题、祸害无穷等的意见

I was a nuisance, an incumbrance, and a pest
我是一个讨厌的东西，一个累赘，和一个祸害。

"As is so often pointed out, knowledge is a two-edged weapon which can be used equally for good or evil. "
人们常说知识是一把双刃刀,它既能造福人类,又会给人类带来祸害。

disaster是什么意思：
n. 灾难，不幸；彻底的失败

to meet with disaster; to suffer disaster; to smart for
遭殃

Knowledge of the disaster soon spread.
灾难的消息很快传开了。

Let's forget the disaster.
让我们不要再把那场灾难放在心上了。

harm是什么意思：
v. 伤害
n. 损害

It will do harm.
它会引起害处的。

Good counsel does no harm
忠言无害

Shit is harmful to your health.
毒品对健康有害。

damage是什么意思：
n. 损害；伤害；赔偿金
v. 损害，损坏

respond in damages
承担赔偿责任,vt.1. 以...回答[+that]n.1. 【宗】(会众对牧师的)应答,唱和,2. 【建】壁联

The majority of the damage is easy to repair.
这次的损害大部分容易补救。

These goods were damaged in transit.
这些货物在运输过程中损坏了。