词根：tend, tens, tent = to stretch（伸）
tend,tens,tent这三个为同源异形根，tend来源于拉丁动词tendere, 意为to stretch（伸开，伸长，延伸）；tens和tent都是这个拉丁动词的动名词词干（tendere有两个动名词形式:tensum和tentum），主要用来构成相应的名词和形容词。
同源词：
1. contend （con<com(=together) + tend(=stretch)相互拉扯，共同伸取某物 --->）
vi. for/with + sth 争辩；争论；竞争
vt. 主张
contention n.争辩，争论
contentious adj.有争议的
Despite what the officer said,the driver contended she was only driving at 30 mph. 不管警察说什么那个司机都争辩说自己的架车时速只有30英里。
2. extensive（向外伸展的 ex(=out) + tens(=stretch)）
adj.广大的；广泛的
extend v.扩展，扩大；伸（手、脚等）(ex出+tend伸展,趋向→伸出去→扩张)
extension n.延长，扩大
extent n.宽度，程度，范围；[律]<英>扣押令
extensively adv.广大地，广泛地
An extensive system of underground aquifers provides water in the Midwest. 大范围的地下蓄水层为中西部地区提供用水。
3. intensive（在...里拉长的 in(=in) + tens(=stretch)）
adj.强烈的；集中的；精深的；透彻的；加强语气，强调的
intensify v.加强
intensification n.激化，强化
intensity n.强烈；极度
intension n.强度
intense adj.强烈的，激烈的；热情的
I took a 2-day intensive course on how to use my new computer. 为学会使用我的新计算机，我参加了一个为期两天的强化培训课程。
4. ostensible（向上拉长的 os<ob(=over,against) + tens(=stretch)）
adj.表面上的，外表上的；面子上的
ostensibly adv.表面上
The ostensible reason for their divorce was "irreconcilable differences". 他们离婚的表面理由是“性格不和”。
5. ostentatious（向某物的反方向拉长的 os<ob(=against,over) + tent(=stretch)）
adj.卖弄的，夸耀的；豪华的，铺张的
ostentation n.夸耀，卖弄；虚饰 （os-(obs-) = in front of 在...之前；tent = to stretch 展开；-ation n. = the act 表行为 --> " the act of stretching one's belongings in front of others 在他人面前展示财物" -->）
ostentatiously adv.卖弄地
We want an elegant but not ostentatious wedding. 我们希望办一场高雅而不铺张的婚礼。
6. pretentious（向前伸展的 pre(=before) + tent(=stretch)）
adj.炫耀的，做作的；狂妄的
pretend v.做作，自负（pre- = before 在...之前；tend = to stretch 伸展 -->" to stretch one's mind before the public 在众人面前展开或夸张自己的想法" -->）
pretense n.虚假；做作
pretension n.自命，自称；做作；假装；借口；托词
pretender n.妄提要求者；伪装者
The people at the coutry club aren't pretentious at all. They're very nice !那个乡村俱乐部的人一点都不狂妄，他们很新切！
7. attend
v.出席，参加；（~to）致力于；护理；陪同，伴随；侍奉 *at<ad(=to)
The lectures were well attended. 听演讲的人很多。
attend to what others are sying 注意听别人说的话
have the honor of attending upon the Prince 很荣幸侍奉王子
My good luck attends you!祝你好运！
8. attendance
n.出席，出勒；出席人数；侍奉，照料 *at<ad(=to)
certificate of attendance 在学证明书
prize for regular attendance 全勒奖
attendance book 出勒簿
large/small attendance 出席人数多/少
in attendance upon the Queen 陪同女王
9. attention (at加强+tent伸展,趋向+ion表名词→伸展出去→注意;照料)
n.注意，注意力；（pl.）殷勤；照料；立正姿势；治疗 *at<ad(=to)
Attention,Mr.Roberts （用在商务文书、公文中）罗伯茨先生亲启
Attention,please! 各位请注意！
attract/draw attention 引起注意
listen with attention 倾听
Pay one's attentions to a lady 讨一位小姐的欢心
Attention! （口令）立正！缩略语：Shun!
receive immediate attention 得到紧急救治
10. attendant
n.侍从；出席者;(pl.)随行人员 adj.伴随的；侍候的，护理的 *at<ad(=to)
attendee n.出席者
the Prince and his attendants 王子及其侍从
famine and its attendant diseases 饥荒和紧随其至的疾病
old age and its attendant evils 老龄及紧随甚至的麻烦
11. attentive (at加强+tent伸展,趋向+ive……的→一再把脑袋向前伸（例如，我们见到老师都要向躬身问好；发现有吸引力的东西特别是看书时，我们都要下意识地伸头）→)
adj.注意的，留意的；专心的；体贴的 ；注意的,有礼貌的
attentively adv.注意地；周到地
attentive to one's studies 专心致志学习的
attentive to her young brother 关心她弟弟的
attentive audience 倾听的观众
12. detente
n.<法>紧张关系的缓和 *de(=down)
13. distend（dis- 散开，tend 伸，扩）
v.扩张，扩大；使膨胀，膨胀 *dis(=away)
distension /distention 膨胀
14. hypertension （hyper- 超高，tension 张力，压力；“血的压力过高”-->）
n.高血压 *hyper(=over,above,excessive)
15. hypotension (hypo在……下面,次等+tension压力[引申血压]→n.血压过低)
n.低血压 *hypo(=under,less)
16. intend （in- 入，tend 伸；“把心思伸向某事”-->打算做某事-->）
v.想要；计划，打算；意指 *in(=into)
intended adj.预谋的，故意的；（n.）已订婚者
Let me introduce you to my intended. 我向你介绍我的未婚妻。
17. intent （in- 入，tent(=tend)）
n.目标；意图；意味，意思 adj.（表情）热切的；（~ on ）专心致志的 *in(=into,intensive)
intently adv.专心地，专注地；热切地
shoot with intent to kill 故意开枪杀人
with good/evil (malicious) intent 善意地/恶意地
to all intents and purposes 事实上
intent on his work 埋头于他的工作的
intent on beautiful scenery 陶醉于美景的
18. intention （同上，-tion 名词后缀）
n.意向，意图，目标，目的 *in (=into,intensive)
with good intentions 善意地
without intention 无意中
with the intention of ~ing（打算做...）
well-intentioned/ill-intentioned 善意地/恶意地
19. intentional
adj.故意的，蓄谋的 *in (=into,intensive)
20. portend （por- = pro- 前，tend(=tent) 伸；出现在...之前的情况或事物-->）
v.预示（未来）；预先警告 *por<per(=through)
Black clouds portend a storm. 乌云预示着风雨即将来临。
21. portent （por- = pro- 前，tend 伸；“伸到前面”-->出现在前面，（某种情况或事物）出现在...之前-->）
n.（不祥的、大事件的）征兆，预兆；迹象；异常的人（或事物）
portentous adj.不祥的，凶兆的；令人惊讶的；自命不凡的
22. superintend
v.主管；监督；指挥 *super(=over),in(=into)
superintendence 主管；监督
23. superintendent
n.监督者，管理者；（企业，机关等的）负责人 *super(=over),in(=into)
superintendent of schools 教育局局长
superintendent of a revenue office 税务局局长
24. tend
v.看管，照料（把注意力伸向某人或某事-->）；倾向，趋向（伸向-->）
25. tendency (tend趋向+ence表名词→n.趋势,趋向)
n.倾向，趋势
strong upward tendency in oil shares 石油类股票的强劲上涨趋势
26. tendentious
adj.倾向性的，有偏见的；宣传性的
tendentious/tendencious reports 宣传性报道
27. tender （tend 伸-->伸出；“刚伸出（长出）的嫩芽”-->）
adj.（色彩、光线等）柔和的；柔弱的；年幼的，未成熟的；敏感的，容易受到伤害的，一触就痛的；棘手的；（肉）易咀嚼的，嫩的；亲切的，温柔的，体贴的 adv.温柔地，亲切地 n.看护人员；补给船；投标；法定货币；提出，提供 v.提出，提供；投标
tender green 嫩江绿
tender skin 娇嫩的皮肤
tender subject 棘手的问题，微妙的问题
tender loin （牛或猪）腰部的嫩肉
tender looks/care 和蔼的表情/温柔的照料
tender tender parents 体贴的父母
tender hearted 心肠软的，富于恻隐之心的
Love me tender. 温柔地爱我
tender his resignation to the president 向总统递交辞呈
28. tendon
n.筋，腱
29. tense（tense 伸，伸开-->拉紧）
adj.拉紧的；紧张的 v.使拉紧，使绷紧；使紧张 n.[语]时态
tensible（见上，-ible 可...的）n.可伸展的，可拉长的
tensity（见上，-ity 表情情况、性质）n.紧张，紧张度
faces tensed with anxiety 焦虑、紧张的面孔
tense atmosphere 紧张的气氛
He tensed his muscles for the effort. 他将自己的肌肉绷起来发力。
He's always tensed up before an exam. 他在考试前总是紧张。
30. tent （tent 伸；能够“伸开（张开）”的东西（如皮革、帆布等），用作掩盖、庇护之用-->）
n. 账篷，帐棚
词根词缀：bull-, bulli-
【来源及含义】Latin: to bubble, a bubble; to blister, a blister
【相关描述】Additional words related to this unit are available at this "bubble" unit.
【相关词根词缀】Cross references of word groups that are related, partially or extensively, to: "blister, bump, swelling": ichor-; papulo-; pemphig-; puro-; pus-; pustu-; pyo-; suppurant-; tum-; vesico-; vesiculo-.
【同源单词】budge, bulla, bulla tympani, bullation, bullectomy, bullition
词根词缀：ichor-
【来源及含义】Greek: fluid [distinct from blood] that flows through the veins of the gods; by extension, "watery part of blood or milk," used in the sense of "thin, serous or sanious fluid, especially from a wound or sore"
【相关词根词缀】Cross references of word groups that are related, partially or extensively, to: "blister, bump, swelling": bull-; papulo-; pemphig-; puro-; pus-; pustu-; pyo-; suppurant-; tum-; vesico-; vesiculo-.
【同源单词】ichor, ichorhemia, ichoroid, ichorous, ichorous pus, ichorrhemia
词根词缀：papulo-, papul-, papuli-
【来源及含义】Latin: pimple, pustule
【相关词根词缀】 Cross references directly, or indirectly, involving the "skin": callus-; chorio-; cicatri- (scar); cori-; cuti-; hymen-; lepido- (scab, scale); psoro- (itch, mange); pustu- (blister, pimple); rhytid- (wrinkle); scabio- (mange, itchy); sebo- (grease, oil). Cross references of word groups that are related, partially or extensively, to: "blister, bump, swelling": bull-; ichor-; pemphig-; puro-; pus-; pustu-; pyo-; suppurant-; tum-; vesico-; vesiculo-.
【同源单词】maculopapular, papilliferous, papule, papulopustular, papulosis, papulosquamous
词根词缀：pemphig-, pemphi-
【来源及含义】Greek: pemphix, "blister"; blistering skin diseases or a swelling of the skin that contains watery fluid and is caused by burning or irritation; a bump or small swelling on or beneath the skin
【相关词根词缀】 Cross references of word groups that are related, partially or extensively, to: "blister, bump, swelling": bull-; ichor-; papulo-; puro-; pus-; pustu-; pyo-; suppurant-; tum-; vesico-; vesiculo-.
【同源单词】benign familial chronic pemphigus, bullous pemphigoid, erythematous pemphigus, pemphigoid, pemphigus contageosus, pemphigus erythematosus
词根词缀：puro-, puru-
【来源及含义】Latin: pus
【相关词根词缀】 Word families with similar applications about: "decay, rotten; wasting away; putrid, pus" word units: phthisio- (decay, waste away); pus (viscous fluid via an infection); pustu- (blister, pimple); putre- (rotten, decayed); pyo- (pus; purulent); sapro- (rotten, putrid, putrefaction, decay); sepsi- (decay, rot, putrefactive); suppurant- (festering, forming or discharging pus); tabe- (wasting away, decaying). Cross references of word groups that are related, partially or extensively, to: "blister, bump, swelling": bull-; ichor-; papulo-; pemphig-; pus-; pustu-; pyo-; suppurant-; tum-; vesico-; vesiculo-.
【同源单词】mucopurulent, purohepatitis, puromucous, purulence, purulency, purulent
词根词缀：pustu-
【来源及含义】Latin: blister, pimple
【相关词根词缀】 Word families with similar applications about: "decay, rotten; wasting away; putrid, pus" word units: phthisio- (decay, waste away); puro- (pus); pus (viscous fluid via an infection); putre- (rotten, decayed); pyo- (pus; purulent); sapro- (rotten, putrid, putrefaction, decay); sepsi- (decay, rot, putrefactive); suppurant- (festering, forming or discharging pus); tabe- (wasting away, decaying). Cross references directly, or indirectly, involving the "skin": callus-; chorio-; cicatri- (scar); cori-; cuti-; hymen-; lepido- (scab, scale); papulo- (pimple); psoro- (itch, mange); rhytid- (wrinkle); scabio- (mange, itchy); sebo- (grease, oil). Cross references of word groups that are related, partially or extensively, to: "blister, bump, swelling": bull-; ichor-; papulo-; pemphig-; puro-; pus-; pyo-; suppurant-; tum-; vesico-; vesiculo-.
【同源单词】acropustulosis, papulopustular, pustulant, pustular, pustulate, pustulation
词根词缀：pyo-, py-
【来源及含义】Greek: pus; purulent, an infection or foreign material that causes a thick whitish-yellow fluid which results from the accumulation of white blood cells
【相关词根词缀】 Word families with similar applications about: "decay, rotten; wasting away; putrid, pus" word units: phthisio- (decay, waste away); puro- (pus); pus (viscous fluid via an infection); pustu- (blister, pimple); putre- (rotten, decayed); sapro- (rotten, putrid, putrefaction, decay); sepsi- (decay, rot, putrefactive); suppurant- (festering, forming or discharging pus); tabe- (wasting away, decaying). Cross references of word groups that are related, partially or extensively, to: "blister, bump, swelling": bull-; ichor-; papulo-; pemphig-; puro-; pus-; pustu-; suppurant-; tum-; vesico-; vesiculo-.
【同源单词】archepyon, arthroempyesis, biopyoculture, biopyocultured, dacryopyorrhea, dacryopyosis
词根词缀：suppurant-, suppura-
【来源及含义】Latin: to fester, to form matter; forming or discharging pus
【相关词根词缀】 Word families with similar applications about: "decay, rotten; wasting away; putrid, pus" word units: phthisio- (decay, waste away); puro- (pus); pus (viscous fluid via an infection); pustu- (blister, pimple); putre- (rotten, decayed); pyo- (pus; purulent); sapro- (rotten, putrid, putrefaction, decay); sepsi- (decay, rot, putrefactive); tabe- (wasting away, decaying). Cross references of word groups that are related, partially or extensively, to: "blister, bump, swelling": bull-; ichor-; papulo-; pemphig-; puro-; pus-; pustu-; pyo-; tum-; vesico-; vesiculo-.
【同源单词】suppurant, suppurantia, suppurate, suppuration, suppurative, suppurative endophthalmitis
词根词缀：tum-, tume-, -tumescence
【来源及含义】Latin: swelling, to swell; swollen
【相关词根词缀】 Cross references of word groups that are related, partially or extensively, to: "blister, bump, swelling": bull-; ichor-; papulo-; pemphig-; puro-; pus-; pustu-; pyo-; suppurant-; vesico-; vesiculo-.
【同源单词】carotid-body tumor, dermoid cyst, detumescence, detumescent, intumesce, intumescence