摇测接地电阻值,宜在土壤电阻率()的时候进行
A.最低
B.平均
C.最高
参考答案:C
吗啡对中枢神经系统的药理作用包括
A.镇痛、镇静
B.镇咳
C.抑制呼吸
D.缩瞳
E.恶心、呕吐
I'll show my ______ to you as soon as they come out.
A.photos B.photoesC.a piece of photo D.pieces of photoes