29.　　 doubt v. – (un)doubtedly ad. – (un )doubted a.

28.　　 die v. – death n. – dead a. – dying a.

27.　　 difficult a. – difficulty n.　 U / C 具体的困难　 *have difficulty in doing sth. 不加“S”

26.　　 develop v. – developed a. – developing a. – development n.

*with the development of

25.　　 detect v. – detective n.

24.　　 destroy v. – destruction n.

23.　　 describe v. – description n.

22.　　 (in)dependence n. - (in)dependent a. - dependable a. - depend v.

*depend on , be dependent on , be independent of

21.　　 depart v. –departure n. (departure time)　 depart for =leave for .

20.　　 deny v. – denial n. – deniable a.