A、
Abstract
B、
Keywords
C、
Reference
D、
Acknowledgement
E、
Cover letter
喵查答案：
Keywords
is always together with abstract.
-
Generally, a complete abstract should include several key elements like the background, the problem, the method, the results, etc. -
Generally, keywords can be more than 6 words in an abstract. -
A good Reference should be authoritative, up-to-date, and journal-targeted. -
Acknowledgement is an unnecessary part in a dissertation.