雅思必备词汇：前缀和后缀（2）　　21.
by-:less important ;near .
　　22.
cata-:down,downwoards.
　　23.
cent-:hundred ,hundredth .
　　24.
circum-:around,round about.
　　25.
con-:together with,wholly.
　　26.
contra-:against,opposit.
　　27.
cross-:through;across;many.
　　28.
de-:down,downward;apart;negative;intensive.
　　29.
deca-:ten.
　　30.
deci- :tenth .
　　31.
demi-:half.
　　32.
di-:double,twice.
　　33.
dia-:through,between,across.
　　34.
dich-:two.
　　35.
dis-:apart; negative;intensive.
　　36.
duo-:two,double.
　　37.
dys-:badly,ill.
　　38.
en-:to make;to put in.
　　39.
epi-:upon.
　　40.
eu-:well.