1、趋势类词汇
　　上升动词类：increase,goup,riseup,growup,jumpup,surge,shootup,keepanupwardtendency
　　下降动词类：decrease,godown,decline,falldown,drop,sink,dip,keepadownwardtendency
　　波动动词类：fluctuate
　　持平动词类：remain the same,stabilize,remain stable,remain constant
　　修饰动词的副词：slightly轻微地，slowly缓慢地，gradually逐渐地，steadily稳定地，rapidly迅速地，moderately温和地，轻微地，significantly明显地，sharply明显地，dramatically急剧地，drastically急剧地
　　上升名词类：increase,rise,growth,jump,surge
　　下降名词类：decrease,decline,fall,reduction,drop
　　波动名词类：fluctuation
　　修饰名词的形容词：slight,slow,gradual,steady,rapid,moderate,significant,sharp,dramatic,drastic
　　2、极值类词汇和表达
　　最高点：reach the peak/top/highest point
　　Increase to the peak/top/highest point(所有上升类的动词都可以替换掉increase)
　　最低点：reach the bottom/lowest point
　　drop to the bottom/lowest point(所有下降类的动词都可以替换掉drop)
　　占的最多：occupy/make up/take up/account for the largest proportion/number/percentage of…
　　占的最少：occupy/make up/take up/account for the smallest proportion/number/percentage of…
　　3、倍数的表达方式
　　Double是两倍/大一倍
　　Increase/decrease three times增长/减少了三倍
　　4、大约的表达方式
　　About/around+数字
　　数字+orso
　　Approximately+数字
　　5、常用的小作文的趋势句式表达
　　句式一：变化主体/图画中主体+趋势动词+副词+时间区间
　　Eg:The number of aged people over 65 increased significantly from 1940-2000.
　　The number of aged people over 65 dropped slightly from 1960-1980.
　　The number o faged people over 65 fluctuated between 1 million and 1.2 million from 1940-1950.
　　The number of aged people over 65 remained stable from 1930-1940.
　　句式二：There be+形容词+表示趋势的名词+in+变化的主体+时间区间
　　Eg:There was an significant increase in the number of aged people over 65 from 1940-2000.
　　There was a slight decline in the number of aged people over 65 from 1960-1980.
　　There was a fluctuation between 1 million and 1.2 million from 1940-1950