仅含有DNA或RNA的微生物是()
A.细菌
B.立克次体
C.梅毒螺旋体
D.衣原体
E.病毒
参考答案:E
注射剂质量检查包括哪些方面?
______ of second language acquisition was developed from the Halliday's theory of first language acquisition.
A. Habit formation theory B. Discourse theoryC. Monitor theory D. Cognitive theory