1. [由此及彼]根据已知单词的词义推断出其同根词的词义。
① recognizable a.可认出的→unrecognizable a.
② recognized a.被认可的→unrecognized a.
③ recognition n.承认→nonrecognition a.
2. [同义相连]将左栏中的单词和右栏中相对应的词义连接起来。
① diagnostic a.认识的，知晓的
② incognizant b.没认识到的
③ cognizant c.诊断的
④ recognizant d.认出的；承认的
⑤ prognostic e.预兆的
3. [寻根问底]指出下列单词的词根并领会其词义的由来。
① prognosticate v.预兆；预言；预示
prognostication n.预兆；预言；预示
prognosticator n.预言者；预测者
② gnosis n.真知
③ gnostic/gnostical a.知的，认识的；有灵智的
④ incognizable a.不可认识的，不可知的
⑤ cognoscente n.博学者；专门家；鉴赏家
4. [节外生枝] gnos有一个近形同义的词根gnor，来自拉丁动词gnorare,意思也是to know。请记住以下几个gnor的派生词。
① ignore v.不顾，不理；忽视
② ignorance n.不知；无知，愚昧
③ ignorant a.不知道的；无知的，愚昧的
④ ignoramus n.浑噩无知的人；笨蛋（提示：i-(in-)=not）
42. grad, gress [L]=to step步
在常用grade，gradual，graduate以及aggress，progress中有两个同源异形根：grad和gress。grad来自拉丁名词gradus，意为step（步），或者来自拉丁动词gradi，意为to step（跨步）；gress来自gradi的动名词词干，意思也是to step（跨步）。
grade [grad=step步；-e→]Ⅰn. step;degree;stage步；级；阶段→Ⅱv.① arrange according to grade按等级分类：to grade the tea给茶叶分级② assign a grade to评级，评分：to grade papers评试卷
▽gradation [grad (e) v.;-ation n.] n.等级；分等级
gradual [grad=step步；-u-;-al a.=of……的→“of steps一步步的”→] a. step by step逐步的：gradual recovery逐渐康复
▽gradualism [gradual;-ism n.] n.渐进主义
graduate1 [grad=step步，级；-u-;-ate v.=to make or take做，取得→“to take a step in receiving education取得接受教育的一步”→]Ⅰv. receive a diploma or degree at a college毕业；得学位：He graduated in mathematics. 他是数学专业毕业的。→Ⅱn. one who graduates, especially from a college（大学）毕业生
▽graduation [graduat(e) v.;-ion n.] n.毕业；授学位
graduate2 [grad=step or degree步，度；-u-;-ate v.=to make做→“to make steps or degrees for measurement做测量用的度数”→] v. mark with degrees in measured units刻度，分度：a graduated glass刻度杯
▽graduator [graduat(e);-or n.] n.刻度器；刻度员
aggress [ag-(ad-)=toward 向；gress=to step 跨步→“to step toward向……逼进一步”→] v. make a first attack;intrude挑衅；侵略：Who aggressed in the fight?谁先动手的？
▽aggression [aggress;-ion n.] n.侵略
aggressive [aggress;-ive a.] a.侵略的；爱寻衅的
aggressor [aggress;-or n.] n.侵略者
progress [pro-=forward向前；gress=to step迈步→“to step forward向前迈步”→]Ⅰn. advancement;improvement进步；发展：Make progress every day.天天向上。→Ⅱv. go forward前进，进步：to progress to the goal朝着目标前进
▽progression [progress v.;-ion n.] n.行进
congress [con-=together一起；gress=to step or go 迈步，走→“going together to meet走到一起聚会”→] n. meeting of delegates for discussion or settlement of problems代表大会：the Congress（美国）国会
▽congressman [congress;-man n.] n.国会议员
congressional [(congress;-ion);-al a.] a.代表大会的；国会的
degrade [de-=downward向下；grad=to step迈步；-e→“to step or go downward向下迈步，走下坡”→] v. lower in grade, value, etc;deprive of office or dignity 降级；贬值；贬黜；堕落：The officer was degraded to the ranks. 该军官被降为士兵。
▽degradation [degrad(e);-ation n.] n.降级；堕落
digress [di-(dis-)=aside偏离；gress=to step迈步→“to step aside步伐偏离”→] v. depart from the main subject 离开主题：Don't digress from the point at issue.别离开争论的要点。
▽digression [digress;-ion n.] n.离题；枝节话
digressive [digress;-ive a.] a.离题的；枝节的
regress [re-=backward向后；gress=to step迈步→“to step backward向后迈步”→]Ⅰn. return;backward movement返回；倒退：the regress of floods洪水的退潮→Ⅱv. go back;move backward返回；倒退：No one can make history regress.谁也不能叫历史倒退。
▽regression [regress;-ion n.] n.回归；倒退
regressive [regress;-ive a.] a.回归的；倒退的
