脊椎横突孔基底部骨折时,CT可表现为横突孔()
A.变小
B.增大
C.分隔
D.完整
E.闭塞
参考答案:D
The writer is very popular with young people ____ he has been dead for many years.
A.ever since
B.even if
C.as if
D.so that
如图,质量为10kg的物体放在水平桌面上,求:
(1)物体所受重力大小;
(2)物体底面积为0.1m2,物体对桌面的压强大小;
(3)用20N的水平推力,使物体在桌面上移动0.5m,推力对物体做的功.