问题
单项选择题
用测氧管测定溶解氧时，应先调整水样流速在（）之间。
A、200ml/min～300ml/min
B、300ml/min～400ml/min
C、400ml/min～500ml/min
D、500ml/min～700ml/min
答案
参考答案：D
搜题请搜索小程序“爱下问搜题”
用测氧管测定溶解氧时，应先调整水样流速在（）之间。
A、200ml/min～300ml/min
B、300ml/min～400ml/min
C、400ml/min～500ml/min
D、500ml/min～700ml/min
参考答案：D
Passage Four
According to the passage, what would happen to healthy cells within 48 hours of exposure to radio waves
A．The number of healthy cells will keep declining as more and more of them die.
B．The number of healthy cells will initially drop before recovering rapidly.
C．The number of healthy cells will be on steady increase throughout the process.
D．The scientists have not yet arrived at any conclusion on this issue.