When _______ there, the postman found the door locked and then stopped _______ the letter in the mailbox on the wall.

A．reaching; putting

B．reached; to put

C．reaching; to put

D．reached; putting

确诊霍乱常用( )

A．肥达反应
B．粪便培养
C．血培养
D．粪便镜检
E．胆汁培养