刀的刃部一般比较薄,刀刃对木块产生的力F可分解为如图所示的两个相同的分力F1,F2,下列说法正确的是( )
A:同样大小的F作用下,刃部越薄,F1与F2越大
B:同样大小的F作用下,刃部越薄,F1与F2越小
C:F越大,F1与F2越小
D:F分解成F1与F2时不遵守平行四边形定则
As you go through this book, you ________ that each of the millions of people who lived through World War II had a different experience.
如图,C岛在A岛的北偏东60°方向,在B岛的北偏西45°方向,则从C点看A、B两岛的视角∠ACB=____°.