前缀bi-(bin-) =two,twice,doubly
汉：来源于拉丁语，意为"two",前缀bin(binoculars)和bis(biscuit)都是它的变形。此外，还有一些表示“数字”的前缀。
在常用词bicycle 中有个表示数目的前缀bi-，它源自拉丁语bis,愿意为twice。bi-最早出现在从法语或拉丁引进的外来语中，是个只与拉丁词根结合的原生词缀。16世纪以后，bi-成为英语中的派生词缀，能与名词、形容词及副词相缀合，构成新词（其中包括生物学与化学的术语），表示two,double,having two,in two ways等含义。bi-在个别单词中读[bI]（如bigamy），一般读[bai]。bin-是bi-的异体，只出现在以元音字母开头的词根中。有一个意思是“生命”的词根
英：word-forming element meaning "two, twice, double, doubly, once every two," etc., from Latin bi- "twice, double," from Old Latin dvi- (cognate with Sanskrit dvi-, Greek di-, Old English twi- "twice, double"), from PIE root *dwo- "two." Nativized from 16c. Occasionally bin- before vowels; this form originated in French, not Latin, and might be partly based on or influenced by Latin bini "twofold" (see binary).
1.half semi(semicircle,semifinal) demi(demigod,demimonde) hemi(hemisphere,hemiplegia)
2.one mono(monopoly,monotheism) uni(unison,unilateral) sol (soliloquy,solitude)
3.two bi(bipartisan,bicentennial) di(diarchy,dilemma) du(dual,duet) twi(twin,twilight)
4.three tri(trinity,triangle)
5.four quadru(quadruped,quadruple) tetra(tetragon,tetralogy)
6.five penta(pentagon,pentameter) quin(quint,quintessence)
7.six hexa(hexagon,hexapod) sexa(sexagenary,sextuplet)
8.seven hepta(heptagon,heptahedron) septa(septangle,september)
9.eight octa(octagon,octopus)
10.nine nona(nonagon,November)
11.ten deca(decade,decagon) deci(decimate,decimal)
12.hundred cent(centurion,centipede) hecto(hectare,hectometer)
13.thousand milli(millennium,millpede) kilo(kilometer,kilogram)
14.many poly(polytheism,polyclinic) multi(multiply,multilateral)
15.all pan(panorama,pandemonium) omini(omniscient,omnivorous)
(1.)bicameral
adj.having two legislative chambers 两院制的 *bi(=two),camer(=chamber)
例句：Our legislature is bicameral;it consists of the house of Representatives and the Senate.我们立法机关是两院制的由参议院和众议院构成。
(2.)biennial
adj.occurring every two years 两年一次的
n.plant that lives two year 两年生植物 *bi(=two),enn(=year)
例句：The biennial convention of the Elks Club international will be held in Toronto this August.爱尔克国际俱乐部每两年一次的会议，将于今年8月在多伦多召开。
(3.)bifocal
adj.adjusted to two different focal lengths;designed for both near and distant vision 双焦点的；眼镜可远视和近视两用的 *bi(=two),foc(=focus)
例句：Bifocal glasses are usually worn by older people.老年人经常使用兼有花镜和近视镜两种用途的眼镜。
(4.)bifurcate
v.divide into two branches （路、江、河等）分叉
adj. two-forked 分叉的 *bi(=two),furc(=fork)
例句：The organization chart shows the company's management is bifurcate;one branch manages food services and the other controls the company's apparel business.从组织图表可以看出，公司的经营分成了两部分，一部分负责餐饮业，另一部分则负责服装加工业。
(5.)binoculars
n.field-glasses(pl.)双目显微镜，双筒望远镜 *bin<bi(=two),ocul(=eye)
例句：Without binoculars I couldn't see much of the game from where I was sitting.没有双筒望远镜，我无法从我坐的位置看清楚比赛。
(6.)bisect
v. cut or divide into two parts 切成两份 *bi (=two),sect(=cut)
例句：The proposed highway sill bisect hamptonville into two separate districts.计划修建的公路将把海姆特比尔分成两个区域。