--- Lots of trees and flowers ________ in Zhangzhou every year.
--- You're right. That makes our city more and more beautiful.
A:are planted
B:were planted
C:will be planted
如图所示,一箱子放在水平地面上,现对箱子施加一斜向上的拉力F,保持拉力的方向不变,在拉力F的大小有零逐渐增大的过程中(箱子未离开地面).关于摩擦力f的大小随机拉力F的变化关系,下列四副图可能正确的是( )
48+108+92+5268×99 125x(27×8) 95x38+38x5