按照国家卫生标准,牛奶的比重要求是()
A.1.028~1.032
B.1.000~1.028
C.0.986~1.000
D.≥1.028
E.≤1.032
参考答案:A
—I’m afraid I can’t go to your party; I have lots of things to do.
—________.
A.Take it easy
B.No problem
C.So what
D.What a shame.
下列哪一个不是串联四级杆质谱具有的扫描模式?()
A.母离子扫描
B.子离子扫描
C.MS3
D.MRM