Mr. F the academic word list (a d)

radical  adj. of or from the root or base; fundamental ulkan, juda muhim

random  adj. done, chosen, etc without method or conscious choice; haphazard tasodifiy
range  n. connected line or row of mountains, hills, etc tizma (tog’, tepalik)
ratio  n. relation between two amounts determined by the number of times one contains the other nisbat, proporsiya
rational  adj. able to reason mantiqiy
react  v. ~ behave differently or change as a result of sth; respond teskari ta’sir ko’rsatmoq
recover  v. ~ sth find again (sth stolen, lost, etc); regain possession of sth topmoq, qayta qo’lga kiritmoq
refine  v. remove impurities from (sth); purify aralashmalardan tozalamoq
regime  n. method or system of government tizim, metod
region  n. part of a surface or bodyor space with or without definite boundaries or characteristic features
register  n. official list or record of names, items, attendances, etc jurnal
regulate  v. control or direct by means of rules and restrictions tartibga solmoq, idora qilmoq
reinforce  v. make stronger by adding material, etc ko’chaytirmoq, mustahkamlamoq
reject  v. refuse to accept rad etmoq
relax  v. (make sth) become less tight, stiff, etc
release  v. ~ sb/sth (from sth) allow (a person or an animal) to go; set free or liberate sb/sth ; qo’yib yubormoq

relevant  adj. ~ (to sth/sb)connected with what is being discussed, what is happening,what is being done, etc aloqador
reluctance  Unwillingness. hohlamaslik
rely  v. (pt, pp relied) ~ on/upon sb/sth (to do sth) count or depend on sb/sth. ishonmoq