引起继发性腹膜炎的细菌主要是（）。A.拟杆菌 B.变形杆菌 C.大肠埃希菌 D.肺炎

- ______ he _____ on the farm(农场)?

-Yes, he does. He's a good farmer.[ ]

A. Does, work    

B. Is, working    

C. Does, do

铅对机体影响的早期变化是

A．卟啉代谢障碍
B．疲乏无力
C．铅面容
D．腹绞痛
E．腕下垂

We put _____ our tent and began to sleep in it, but I really couldn't put _____ the heat in the tent. [ ]

A. up; off

B. up; up with

C. on; out

D. over; into

等渗性脱水的治疗应是

A．按需补给平衡液

B．周围循环衰竭时先补足血容量

C．同时纠正酸碱失衡

D．低钾时及时补钾

E．输液时应先胶后晶