进行样品比色测定时,在波长()nm处、以()为参比,用1cm比色皿,测定各样品的吸光度。
A.540,蒸馏水
B.540,吸收液
C.590,蒸馏水
参考答案:A
根据短文内容及首字母提示补全单词(共10小题;每小题1分,共10分)
The Yellow Mountain is o小题1: of the most famous mountains in China. It is in the south of Anhui. Every year t 小题2: of Chinese and foreigners pay a visit here. It’s not f 小题3: from here. It t 小题4: you about three hours to get there by bus. You can also go there by train or by plane. While you are c 小题5: the mountain, you can e 小题6: the sea of clouds, wondrous pines and unique rocks ahead of you. In the e 小题7: morning when the sun rises, the sky looks b 小题8: . It’s my d 小题9: place to v 小题10: .
按照计入指数的项目多少不同,指数分为()。
A.加权指数和简单指数
B.简单指数和综合指数
C.个体指数和综合指数
D.质量指数和数量指数