如图所示，A、B两木块叠放在水平地面上，则地面受到的压力是
A．A和B对地面的压力之和
B．只有B对地面的压力
C．B的重力
D．A和B的重力之和
答案：B
亚洲的地势特点是 [ ]
A．中间高、两边低
B．中间高、四周低
C．东西低、南北高
D．中国高、伊朗低
From his _____ look on his face, the train must have left. [ ]
A. disappointed
B. disappointing
C. satisfied
D. satisfying
