乙酰苯胺的合成实验中，回流装置中用来冷凝的仪器是（）。
A. 直形水冷凝管
B. 球形水冷凝管
C. 空气冷凝管
D. 刺形分馏柱
查看答案
乙酰苯胺的制备除了可以用醋酸作酰化试剂外，还可以采用其它的什么酰化试剂？
A. 乙酰氯
B. 乙酸乙酯
C. 乙酸酐
D. 乙腈
Phrase structure rules allow us to better understand _____.
A. how words and phrases form sentences.
B. what constituties the grammaticality of strings of words.
C. how people produce and recognize possible sentences.
D. all of the above.
Syntactic movement is dictated by rules traditionally called ____.
A. transformational rules
B. generative rules
C. prhase structure rules
D. x-bar theory
____ is defined as the study of sentence structure.
A. Mophology
B. Semantics
C. Phonology
D. Syntax
微信支付 
支付宝支付