— Now more and more people have realized that drugs do great harm to people’s health and their families.

— Quite true, so everyone should          them.

A．throw away

B．keep away from

C．put away

D．give away

如图所示，某质点沿半径为r的半圆弧由a点运动到b点，则它通过的位移和路程分别是

A 2r方向向东  πr

B. r，方向向东  πr

C. 2r 方向向东  2r

D. 0  0