竞争性抑制维生素K，使维生素K依赖因子合成受阻。（）
A.肝素
B.香豆素类
C.链激酶
D.尿激酶
E.阿司匹林
参考答案：B
压路机的滚筒是圆柱形，长是1.5m，滚筒的半径是0.54m。如果滚筒每分钟转动16周，则压路机每分钟可压路面约() m2。
A．58
B．69
C．76
D．81
He can't seem to a steady job; every two years or so he quits it, moves to another city
and starts again.[ ]
A. settle down
B. settle in
C. settle up
D. settle on
