下列计算正确的是
A:am·a2=a2m
B:a32=a5
C:x3·x2·x=x5
D:a3n-5÷a5-n=a4n-10
Lucy didn't feel well last week. She ____ all day and all night.
①计划生育 ②科教兴国 ③对外开放 ④保护环境