超声识别结肠的特征性标志是：()
A．结肠内径较小肠大
B．结肠袋与半月襞
C．结肠壁比小肠厚
D．结肠位于中上腹
E．结肠内容物多，且回声高
参考答案：B
It is illegal for a public official to ask people for gifts or money _______ favors to them. [ ]
A. in preference to
B. in place of
C. in agreement with
D. in exchange for
朗肯土压力理论和库伦土压力理论的假定条件分别是什么？
