如图所示,重力为的物体在水平向左的恒力的作用下,静止在倾角为的固定光滑斜面上.下列关于物体对斜面压力的大小的表达式,正确的是()
A.
B.
C.
D.
参考答案:A, B
Some disputes among these countries are ______ by history. A. left over B. turned over C. handed over D. taken over
古建筑的火灾危险性有哪些?