词根：rat, ratio = to reckon（推定）, reason（理由；理

  词根rat,tatio来自拉丁语的ratio 意为 “to reckon,reason”,-ratio- 为词根 -rat- 的变体， 有异形同义词根：arithm,calc,count 计算。

同源词：

1. ratify vt.批准；认可 《-ify动词词尾》
  ratification n. 批准；认可
  Iheartily fatify your choice of restaurants.你很会选餐厅，对此我由衷地认可。

2. rate n.率，比率；价格，费用；速度；等级 v.评价；估价；列为
  birth/death rate（出生/死亡率） exchange rate （汇率） walk at the/rate of 3miles an hour（以每小时3英里的速度行走） at a great rate（高速地）

3. rating n.等级；测试得分；评分；<英>水兵，普通海员；声誉；（电视节目的）收视率，（广播的）收听率
  efficiency rating system （效率评分系统）

4. ratio n.比，比率
  direct/inverse/nutritive ratio（正比/反比/营养比值）;ratio 3:2（（读作 the ratio of three to two）3:2的比率）

5. ratiocination n.（尤其指用三段论法的）推理 《cin=kin=to rnove》

6. ration n.定额，定量，（食品等的）配给（量）；(pl.)[军]（日需）口粮；（日需）给养
         v.定量供应（粮食、水等）；平均分配
  ration card/book（定量供应卡/（定量）配给票证簿） go and draw rations（去领取分发的东西）ration the water（定量供水）

7. rational a.理智的；理性的；合理的
           adv.rationally（理性地；合理地）
           n.rationality （理性观点（或行动）；合理性）
  rational conduct/explanations（合理的行为/解释）

8. rationale n.理论；原理；理论基础

9. rationalism n.唯理论；理性主义《-ism=主义》
  rationalist n.理性主义者；唯理性论者
  rationalistic adj.理性主义（者）的；唯理论（者）的

10. rationalize v.使合理；合理地解释；用理论来说明；使合理化

11. rationality n.理性；合理

12. rationalization n.合理化；（数学）化根式为有理式

13. irrational adj.不合理的；无理性的《ir- = in- =not》

14. irrationality n.不合理；无理性；无知

词根：calc, calcul = lime, stone, to reckon 石灰, 石头, 计算

  来源于拉丁语 calx/calculus 石灰石 / 计算。同义词根有来自拉丁语的rat。-calci- 为 -calc- 的变体，有同形异义词根：-calc- 踢 / 踩；有同类词根（钙和硫都属于化学元素）：-sulf- / -sulph- 硫，而词根 -sulph- 也可以理解为是根据辅音的交替规律由 -sulf- 变来的，属于单 / 双辅音交替规律，如：sulfur 硫磺、sulfite 亚硫酸盐、sulphur 硫磺、sulphite 亚硫酸盐。

同源词：

1. incalculable（无法计算的in(=not) + calcul(=reckon)）
  adj.无法计算的，（数目）巨大的；不可预测的
  Prime numbers of more than 100 digits are inclculate by today's supercomputers.今天的超级计算机也无法计算出超过100位的素数。

2. calculable
  adj.计算的；可信赖的

3. calculate
  v.计算；推算；打算
  calculating adj.计算的；审慎的
  calculated adj.计算出的；精心计划的；故意的；可能的
  calculated crime 蓄意犯罪
  calculator n.计算器；计算者

4. calculation
  n.计算；仔细的分析（或思考等） 
  after much calculation 深思熟虑后

5. calculus
  n.计算法；微积分；结石

6. chalk  [calc 石灰，音变；c → ch,c→k,因此：calc → chalk;由“石灰”制成的→]
  n.粉笔

7. calcarious  [calc 石灰，-arious  复合后缀，...的]
  adj. 石灰质的

8. calcic  [-ic (a.) 表示“…的”]
  adj. 石灰的,含钙的,钙质的

9. calcimine  [-imine (n.) 名词后缀]
  n. 刷墙粉

词根：mers, merg = to dip, to plunge

  来自拉丁语的merg,mers意为to dip,to plunge。

  （*拉丁文mergere(=to sink,to dip),过去分词mersus。—— 英文字根字典）

同源词：

1. immerse（向内浸、浸湿im<in(=into) + mers(=dip,plunge)）
 vt.sb/sth + in + sth 浸入；使深陷入；使埋首于；给...施浸礼
  immersion n.沉浸；专心；浸礼 cf. immerge (=immerse)
  He immersed himself in his studies to the detraction of his social life.他因埋头于学业而忽视了社交生活。

2. emerge
  v.出现；浮现；（事实、想法等）显现出来 *e<ex(=out)
  emergence n.显现，出现
  emergent adj.显现的，出现的；新兴的
  emergent countries of Africa 非洲的新兴国家
  The moon emerges from behind the clouds.月亮出现在云层后面。

3. emergency
  n.紧急情况，突然事件 *e<ex(=out)
  emergency power 紧急备用动力
  emergency exit/ fund 紧急出口/应急奖金
  emergency call 紧急呼叫
  emergency case/box 急救箱
  emergency measures 应急措施

4. submerge
  v.把...浸入水中；淹没；潜入水中 *sub(=under)
  submergence / submersion 淹没，浸没
  submersible adj.能潜入的

5. submerged
  adj.浸没的；浸在水中的；陷于贫困的；[海]水下的；水下运行的 *sub(=under)
  submerged at high tide 涨潮时被淹没的遇难船只
  submerged rocks 暗礁
  wreck that is submerged speed 水下行驶速度
  submerged tenth 社会的最底层

6. merge
  v.（使）合并；（使）渐渐消失
  merger n.（公司等的）合并
  mergence n.没入；消失
  The small banks were merged into one large organization. 那家小银行被并入一家大机构。
  His fear was gradually merged into curiosity. 他的恐惧逐渐被好奇心所代替。

7. immerge
  v.浸入；使陷入（沉没其中）《im- = into》

词根：chal = warm, ardent

  来自拉丁语的chal意为warm,ardent。
nonchalant （不温暖的或不热烈的 non (=not) + chal (=warm,ardent)）
  adj.冷漠的，冷淡的，没有热情的；泰然的
  nonchalance n.冷漠，冷淡
  You're so nonchalant. Flying makes me a nervous wreck!你是这么泰然自若。飞行可让我神经紧张！

词根词缀：censur-, censor-

【来源及含义】Latin: to count, to reckon, to assess, to estimate, to value, to deem, to judge; judgment, criticism; Latin censura and French censure

【同源单词】censive, censor, censorate, censorial, censorian, censoring

词根词缀：numer-, number-

【来源及含义】Latin: distribution; to count, to reckon

【同源单词】alphanumeric, alphanumerical, alphanumerics, annumerate, annumeration, apocalyptic number

词根词缀：psepho-, pseph-

【来源及含义】Greek > Latin: pebble/pebbles, stone/stones; election; vote

【相关描述】To cast one's vote with a pebble, to count, reckon; from small stone, pebble [used in counting or voting]. Pebbles were used in ancient Greece for casting votes, and so psephos came to metaphorically mean, "vote".

【同源单词】isopsephic, psephism, psephite, psephocracy, psephocrat, psephograph

词根词缀：put-, puta-, -pute, -puter, -puting, -putate, -putation, -putative

【来源及含义】Latin: putatus past participle of putare: to think over, consider, reckon, count; to trim, prune, lop, cut, clean, clear, unmixed

【相关描述】From Latin, puto-, putare: literally; especially of trees, "to lop, to prune" and "to cleanse, to clear"; then (1) "to clear up, to settle"; especially, of accounts; (2) "to reckon, to estimate, to value"; (3) "to consider, to hold, to believe, to think".

【相关词根词缀】 Related cutting-word units: cast-; castrat-; -cise, -cide; -ectomy; mutil-; sec-, seg-; temno-; -tomy; trunc-.

【同源单词】account, account, accountability, accountable, accountably, accountant

词根词缀：ratio-, reason-

【来源及含义】Latin: reckoning, to reckon; calculating, calculation; understanding; thinking

【同源单词】arraign, arraigner, arraignment, derationalize, irrational, irrationalism

词根词缀：temer-

【来源及含义】Latin: rashly; at random, by chance; blindly; reckless; foolishly

【相关词根词缀】 A cross reference of other word family units that are related directly, or indirectly, to: "chance, luck, fate": aleato-; auspic-; cad-; fortu-; -mancy; serendipity; sorc-; tycho-.

【同源单词】temerarious, temerariously, temerariousness, temerary, temerat, temeration