Which of the following statement about abstract is NOT correct?

A.An abstract contains key words found in a research paper, thesis, or review.

B.Components of an abstract vary according to different disciplines.

C.An abstract is an excerpted passage from a research paper, thesis, or review.

D.The length of abstracts varies according to discipline and the length of the work.

正确答案：An abstract is an excerpted passage from a research paper, thesis, or review.