PT主要检测______凝血系统功能，APTT主要检测______凝血系统功能。
参考答案：外源性,内源性
----Why are you so tired these days?
----- Well, I have _____homework to do.
A．too much
B．too many
C．much too
D．many too
急性肺炎病程为
A．2个月内
B．1个月内
C．3个月内
D．4个月内
E．5个月内
