fast 用作副词表示程度，主要有三个搭配。

1. fast asleep 熟睡

They were both fast asleep in their beds. 他们俩在各自的床上都熟睡了。

There were two dogs on the porch. Both were fast asleep. 门廊上有两条狗，都在熟睡。

When he went upstairs five minutes later, she was fast asleep. 他5分钟后上楼时，她已熟睡。

2. be stuck fast 被紧紧夹住

The boat’s stuck fast in the mud. 那条船陷在泥里动弹不得。

The tanker is stuck fast on the rocks. 油轮紧卡在礁石中间动弹不得。

I couldn’t budge the drawer—it was stuck fast. 我拉不动抽屉——卡死了。

3. be held fast 被紧紧粘住

Walter held fast to the rope. 沃尔特紧紧地抓住绳子。

He held fast to his principles. 他坚持自己的原则。

The ship was held fast by the anchor chain. 船被锚链牢牢地稳住了。