高分子激肽原( )
A．参与止血过程B．参与凝集过程C．参与纤溶激活过程D．参与纤溶抑制过程E．参与抗凝过程
参考答案：B
当一对标准的圆锥齿轮传动时，必须使两齿轮分度圆锥相切，两锥顶重合，装配时据此来确定小齿轮的轴向位置。（）
At the science museum，the students from Sunshine Middle School get to know__________.
A．what is the spaceship like
B．what the spaceship looks like
C．how the spaceship looks 1ike
D．how does the spaceship 1ook like
