The idea of cloning extinct dinosaurs _____ a mixture of fear and excitement into people’s hearts, as evidenced by the popularity of Jurassic Park.

A．knocked

B．hit

C．struck

D．beat

病原携带者作为传染源意义的大小，主要取决于（）。

A.所携带病原体的型别、毒力 

B.携带病原体时间的长短 

C.排出病原体数量的多少 

D.有无间接排出病原体 

E.病原携带者的职业和个人卫生习惯