TOEFL Reading: ETS-TOEFL阅读机经 - LKCH80P46Q5P5PK4L$

Paragraph 4 supports all of the statements about genes EXCEPT: A. Our understanding of the extent to which genes act independently has changed over time. B. Genes are classified into groups on the basis of their function. C. Some genes seem to have no function. D. Studies to identify ways that genes interact have been largely successful.