如图,重量为G的物体A在大小为F的水平向左恒力作用下,静止在倾角为α的光滑斜面上。下列关于物体对斜面压力N大小的表达式,正确的是
A.
B.
C.
D.
ABD
In this lecture, I can only give you a purely view of how we can live life to the full and make some suggestions about the future.
A.private
B.personal
C.unique
D.different
直流馈电线的每对馈电线应保持()。