動詞 let off:

1. grant exemption or release to
   同義詞：excuse, relieve, exempt

1. The janitor let off some steam because the pressure was too high.
   由于壓力過高，火爐工放掉了一些蒸氣。
2. The boys were letting off fireworks.
   男孩子在放煙火。
3. We've been let off school today because our teacher is ill.
   今天學校放假，因為我們的老師病了。
4. She was let off with a fine instead of being sent to prison.
   沒讓她入獄，而是罰款了事。