预应力钢筋的强度标准值，应具有不小于（）％的保证率。
A．100
B．95
C．85
D．80
参考答案：B
A. I have to check if there’s a room available.B. I’ve just arrived from Nanjing.C. Thank you. No problem.D. Have you made a reservation, sir (Dialogue- 1) ( R-receptionistG-guest)
R: Good evening, sir. May I help you G: Yes, please. ________ Can I have a room
液体的惯性力属于（）。
A.摩擦力
B.表面力
C.质量力
D.重力
