在气相色谱中,直接表征组分在固定相中停留时间长短的参数是( )。
A.保留时间
B.调整保留时间
C.死时间
D.保留体积
参考答案:B
短语:从方框中选择适当的短语,并用其适当的形式填空,有两个多余项。
(每题1分,共5分)
1. ________________ you’ve got a chance, you had better make full use of it.
2. I think the photos can ________ us ________ the days we spent together in the country.
3. When they crossed the Rocky Mountains, they managed to _____________ some mountain goats.
4. He wrote a long moving poem ________________ those who died in the war.
5. It is not polite to ____________ other people.
依次执行以下命令后的输出结果是______。SET DATE TO YMD SET CENTURY ONSET CENTURY TO 19 ROLLOVER 10SET MARK TO "."CTOD("49-05-01")
A.49.05.01
B.1949.05.01
C.2049.05.01
D.出错