To be an artist is not easy, but sometimes dreams can be a rich source of ________—for an artist.
A:occasion
B:identification
C:inspiration
D:occupation
隋朝运河“北通涿郡,南至余杭,商旅往返,船乘不绝。”这表明运河的直接作用是( )
甲施工队每天修路a米,乙施工队每天修路b米,需要修路的工程量为3000米。甲施工队比乙施工队每天多修路20米,列出等量关系式为____。