Definition
This idiom describes doing something immediately and without any hesitation.
立即，驚人地
She is very keen on traveling and will leave at the drop of a hat if there's a chance.
她非常热爱旅行，只要有机会就会立刻出发。
He is a very helpful person and will offer assistance at the drop of a hat.
他是一个非常乐于助人的人，会毫不犹豫地提供帮助。
The company is known for its quick response, they can deal with customer's needs at the drop of a hat.
这家公司以快速反应著称，他们可以立即处理客户的需求。