Let down

使失望

His favorite soccer team let him down.

他最喜欢的足球队让他失望了。

Let in

让…进来; 进入

I opened the door and let my dog in.

我打开门，让我的狗进来。

My shoes are starting to let water in due to the heavy rain.

由于大雨，我的鞋开始渗水了。

Let off

原谅；饶恕； 燃放

He is so bad. I guess that girl is not going to let him off this time.

他太坏了。我猜那个女孩这次不会原谅他。

People are not allowed to let off fireworks during Spring Festival in this city.

在这个城市，春节期间不准人们放烟花。

Let on

泄露；假装

Don’t let on about our secrets.

别泄露了我们的秘密。

Let out

放出；泄露；释放

Irene let out a sigh when she saw the scores.

艾琳看到分数时叹了一口气。

You’re too nervous. Take a deep breath and let it out slowly.

你太紧张了。深呼吸，然后慢慢地呼出。

Let the bird out of the cage.

把鸟从笼子里放出来。

Someone has let out the state secrets.

有人泄露了国家机密。

Don’t let the cat out of the bag.

不要泄露秘密。

Let up

停止；放松；减少

After five hours the rain finally let up.

五个小时后，雨终于停了。

I have to let up a little bit, or I might fall apart.

我必须放松一点，否则我可能会崩溃。