A：由a=可知，a与r成反比
B：由ω=2πf可知，ω与f成正比
C：由v=ωr可知，ω与r成反比
D：由a=ω2r可知，a与r成正比
The doctor says that you will end up in hospital _________ you go on smoking like that.
A.Ag
B. Zn
C.Mg
D.____
