heave a log的用法和样例：
- They are sawing a log into planks.
- I bury my face in my hands and heave a sigh.
- He heave a sigh of relief when he find his wallet.
- A picture of a cat on a log is a rebus for catalog.
谜画中有一只猫(cat)站在一块木头(a log)上, 谜底是catalog(目录)。
- A log got in his way as he drove.
- But dancing is as easy as falling off a log.