我国已决定停止进口外国未经检验的血液制品，防止艾滋病的传入，这项措施属于材（ ）
A．控制传染源
B．保护易感者
C．切断传播途径
D．人工免疫
答案：C
As the film star began to appear，the children watched, ________.
A．fascinating
B．fascinated
C．being fascinated
D．having fascinated
______is known to us all, only the theory ______ on practice can be practical.
A．Which; base
B．Which; based
C．As; based
D．As; basing
