一位同学要用已调平的托盘天平称量2.5g药品,在称量中他发现天平指针向左偏移,这时他应该( )
A:移动游码
B:向右盘中加砝码
C:减少药品
D:调节平衡螺母
下列古语中能体现尊重他人,平等待人要求的是( )
The price system is a complex network composed of the prices of all the products bought and sold in the economy as well as of a great number of services.