某工厂有煤120吨，每天烧a吨，烧了3天后还剩______吨．
根据题干分析可得，烧了3天后还剩下：120-3a吨，
故答案为：120-3a．
I was paid last week，but I can’t remember the exact_________ of the money.
A．number
B．value
C．amount
D．percent
