Which of the following best describes the effect of a competitive antagonist on the dose-response curve?()
A. Non-parallel left shift
B. Non-parallel right shift
C. Parallel left shift
D. Parallel right shift
E. No pacts on dose-response curve
查看答案
. Drugs that are administered IV are ()
A. Rapidly absorbed
B. Subject to first-pass metabolism
C. 100% bioavailable
D. Rapidly excreted by the kidneys
E. Rapidly metabolized by the liver
土样内摩擦角为30°,粘聚力为20kPa,土中大主应力和小主应力分别为σ1=300kPa,σ3 =100kPa,则该土样达到的状态为:_____
A. 稳定平衡状态;
B. 极限平衡状态;
C. 破坏状态;
D. 饱和状态.
挡土墙后面的填土为中砂,其内摩擦角为30°,墙背铅垂,土面水平,则墙后产生主动土压力造成土体破坏时,土中破坏面与墙背面的夹角为( )。
A. 30°
B. 31°
C. 45°
D. 60°
厚度为10m的粘土层,上覆透水层其压缩应力为235kPa,下卧不透水层其压缩应力为157kPa,粘土层的初始孔隙比e1=0.8,压缩系数a=0.00025kPa-1。整个土层在该应力下压缩量为( )(四舍五入)。
A. 271mm
B. 272mm
C. 273mm
D. 274mm