当样品气各组分不能全部流出色谱柱，或检测器不能对各组分都产生响应信号，而且只需对样品中某几个出现色谱峰的组分进行定量时，可采用（）。
参考答案：内标法
补全对话，每空一词。
Clerk: Can I help you?
Mary: Yes, 1 . I want a sweater.
Clerk: What 2 do you want?
Mary: Blue.
Clerk: Here you are.
Mary: 3 ______ 4 ______ is it?
Clerk: Nine dollars.
Mary: I'll 5 ______ it. Thank you.
Clerk: You're welcome.
锅炉如何进行辅机的保养？
