以下检测器属于总体性能检测器的是()检测器。
A.紫外
B.安培
C.化学发光
D.示差折光
参考答案:D
仔细阅读课本P8 的课文,回答下列问题。
1. Who wrote this letter?
______________________
2. When did Jenny write the letter?
3. Who is Danny’s new friend?
4. Whose parents work in a restaurant?
5. Did they play football after school?
旅游区(点)的质量等级的评定应严格按照“自检、______、初评、______、审批、______”的程序进行。