A、数字类：data,figure,rate,ratio,percentage,propotion,demography,statistics,number(of),one, two,…,first,(雅思阅读基本信号词中最常见的'一类)
B、时间类：day,week,month,March,July,..,1946,1997,…,year,quqrter(-ly),future,now, past,present,recent(-ly),early,late,last,history,traditionally,old,new,no
longer,before,century, BC,AD,time,annually,minute,hour,etd;(雅思阅读基本信号词中最常见的一类)
C、程度类：increase,decrease,reduce,recede,rise,reduction,recession,more,less,-er,-east,most;(雅思阅读基本信号词中最不容易被发现的一类)
D、定义类：process,phenomenon,situation,condition,change,inference,implication, assumption,definition,explanation,evidence,fact,be,as,be viewed that,which,define,etc; (雅思
阅读基本信号词中最容易被忽视的一类)
E、肯定与否定类：but,however,yes,no,not,than,problem,difficulty,pressure,claim,(a)few, (a)little,more(less),任何负面词汇，etc; (雅思阅读基本信号词中最容易被混淆的一类)
F、顺序类：and(两个以上)，then,also,previous,next,first,second,last,finally,order,sequence, “,”(两个逗号同时使用或更多)，“→”，a,b,c排列，1，2，3排列，etc;
G、因果类：由“this”指示的前后句子，by,and,when,if,in order to结构，because,since,as, effect,impact,conclusion,result,consequence,lead to,give rise to,etc.(雅思阅读基本信号
词中最常见的一类)
H、比较类：compare,comparison,positive and negative,adequate and inadequate,past and future,etc;
I、标点符号和特殊印刷类：引号“”，括号()，破折号——，斜体字，粗黑体字，任何大写词，缩写词等等;
J、方向、位置类：south,north,east,west,on the top of,on the bottom of,above,below,beneath, under,in the center of,in the middle of,between…and…,on the left(right)
of,behind,beyond,in the front of,over,here,there,against,on the surface of,near(to),etc;(雅思阅读基本信号词中最容易被忽视的一类)
