汞量法测定青霉素钠时,所用试剂
A. 青霉素酶
B. 醋酸盐缓冲液(PH4.6)
C. 咪唑溶液
D. 正十四烷的正己烷溶液
E. 茚三酮溶液
In Hallidays view, the______function of language is realized as the transitivity system in
A. ideational
B. interpersonal
C. textual
D. social
Consider the following words and finish two tasks: For each word, determine whether it is
Each of the following words can be either a noun or a verb. record outline report journey