外源性激活途径的起始因子是（）
A.Ca2+
B.抗凝血酶Ⅲ
C.血小板因子Ⅲ
D.因子Ⅻ
E.因子Ⅲ
参考答案：E
He said,“What’s the matter?”
→He asked .
A．what the matter is
B．what the matter was
C．what is the matter
D．what was the matter
地方性斑疹伤寒的病原体是（）
A.伤寒杆菌
B.恙虫病立克次体
C.莫氏立克次体
D.副伤寒杆菌
E.普氏立克次体
