The development of the internet over the past 20 years has not only changed the way most people live their lives, but also provided a plethora of new platforms for business. The advertising industry adopt the micro blog as a ______ tool, which is a pertinent example.

A．availability
B．promotional
C．encryption
D．payment

胎儿娩出后已超过30分钟，胎盘尚未娩出（）

A．内出血 

B．外出血 

C．腹腔出血 

D．颅内出血 

E．血尿