【单选题】Why is the air quality tested every day?
A.
Just in case someone asks.
B.
Scientists like to take tests.
C.
Scientists are not very busy.
D.
To keep track of pollution levels.
【单选题】发动机温度过热时,以下哪个描述是错误的( )
【单选题】It is bad manners for you to say ______ when someone asks you a question.
【单选题】发动机温度过热时,以下哪个描述是错误的:
【多选题】下列关于精密度的说法中,正确的是
D.
方法精密度RSD可接受限度要求不依据常量分析和痕量分析而变化。