食管内测压时，正常的压力分区是几个分区（）.
A.一个
B.二个
C.三个
D.四个
E.五个
参考答案：C
--Have you heard about Apple iPhone 4s?
---Sure．It is very hot these days．I’m thinking about getting _______．
A．them
B．one
C．that
D．it
操作间在井场如何摆放？
