提示问题:
1) How often do you exercise?
2) What's your favourite sport? Why?
3) When do you do sports?
已知函数ω>0f(x)=3sin(ωx-π6)(ω>0)和g(x)=3cos(2x+φ)的图象的对称中心完全相同,若x∈0,π2,则f(x)的取值范围是 ( )
下列各种物质的用途叙述错误的是( )