下列计算正确的是[ ] A．x2x4=x8 B．x6÷x3=x2 C．2a2+3

— Could I use your computer for a few moment,please?

— ________.I'm not using it myself.[      ]

A. Come on  

B. It depends

C. Go ahead  

D. That's great

初产妇，足月临产10小时，破水7小时，宫缩20秒1（8~10）分，胎心180次／分，羊水Ⅱ度污染， * * 检查：宫口开大5cm，S=0，矢状缝在右斜径上，小囟门在7点处，坐骨棘突，坐骨切迹<2横指，骶骨浅弧。

下列哪项诊断是正确的（）

A.胎膜早破

B.ROP

C.中骨盆狭窄

D.胎儿窘迫

E.继发性宫缩乏力

F.持续性枕后位

—When did you last hear _____ Jay?

—He phoned me this morning, and we agreed____ a time and place to meet.

A．of, to

B．about, with

C．from, with

D．from, on

吸入气雾剂的微粒大小的最佳范围是（）

A.0.005～0.01μm

B.0.5～5μm

C.10～100μm

D.500～1000μm

E.1000～5000μm