1. [举一反三]根据已知单词的词义推断出其同根词的词义。
expel驱逐→① expeller n.
→② exopellee n.
→③ expellable a.
2. [寻根问底]指出下列单词的词根并领会其词义的由来。
① pulse n.脉搏；脉动；脉冲
pulsar n.脉冲星
pulser n.脉冲发生器
② pulsate v.搏动
pulsative a.脉动的
pulsator n.搏动的东西；搏动式人工呼吸器；脉动器
pulsatory a.能脉动的
③ pulsimeter/palsometer n.脉搏计
④ pulsion n.推进
pulsive a.推进的
3. [节外生枝] pel有个来自法语的异体peal，请注意下列单词。
① peal n.响亮持久的声音
② appeal v.呼吁；恳求
appealing a.有感染力的；动人的
③ repeal v.撤消（决议等）；废止（法令等）
repealer n.撤消者；废止者
68. pend, pens [L]=to hang, to weigh, to pay悬挂，称量，支付
pend和pens是同源异形根，它们来自拉丁动词pendere和它的动名词pensum。这个动词有三个意思：to hang（悬挂）；to weigh（称量）和to pay（支付）。三个意思都与古罗马时用天平“称量”金银“支付”费用一事相关联，而称量的东西是必须“悬挂”在天平上的。三者之中，“悬挂”是基本义。
depend [de-=down下；pend=to hang悬挂→“to hang down form some-thing挂在某物下”→“be supported by something靠某物支持”→] v.① rely (on)依靠；依赖：All living things depend on air.万物生长都有赖于空气。② be determined取决于：Whether we go for an outing depends on the weather.去不去郊游要看天气而定。
▽dependence [depend;ence n.] n.依靠；从属
dependant [depend;-ant n.] n.受赡养者；侍从
dependent [depend;-ent a.] a.依靠的；由……决定的；从属的
independent [in-=not不；dependent a.依赖的→] a.① not relying on独立的：independent thinking独立思考② self-governing自治的：inde-pendent country主权国家
▽independence [in-;depend;-ence n.] n.独立；自主
independency [in-;depend;-ency n.] n.独立；独立国
suspend [sus-(sub-)=under在……之下；pend=to hang悬挂→“to hang under挂在……之下”→] v.① hang from a supporter above吊；悬：The lamp is suspended from the ceiling.电灯从天花板挂下。② put off for a period of time使悬而不决，暂停：to suspend talks中止会谈
▽suspense [sus-;pens;-e] n.悬而不决；未定
suspensor [sus-;pens;-or n.] n.吊绷带
suspension [sus-;pens;-ion n.] n.悬，吊；暂停，中止
suspensive [sus-;pens;-ive a.] a.暂停的；悬而未决的
append [ap-(ad-)=to到；pend=to hang挂→“to hang to a main body挂到某主体上”→] v. add附加：I want to append some words to the drawing.我要给图样附上文字说明。
▽appendage [append;-age n.] n.附加物；附属物
appendant/appendent [append;-ant/-ent a.] a.附加的；附属的
pendulum [pend=to hang挂；-ulum (-um) n.=thing物→“thing that hangs悬挂着的东西”→] n. thing hanging from a fixed point so as to swing freely, as in a clock悬摆；钟摆：simple pendulum单摆
▽pendular [pendul(um);-ar a.] a.钟摆运动的；摆动的
pendulous [pendul(um);-ous a.] a.悬垂的；摆动的
以下分析几个包含“称量”或“支付”概念的同根词。
expend [ex-=out出；pend=to pay支付→] v.① pay out, or spend付出；花费：He expended lots of time in writing this book.他花许多时间写这本书。② use up用尽：Don't expend your energy on such a foolish business.别在这种蠢事上耗尽精力。
▽expenditure [expend;-iture n.] n.支出；支出额
expense [ex-;pens;-e] n.花费；消耗
expensive [ex-;pens;-ive a.] a.花费多的；昂贵的
dispense [dis-=apart分开；pend=to weigh称；-e→“to weigh apart from the amount从总量中称出一部分”→] v.① deal out;distribute分发；分配：The machine dispenses coffee to anyone who puts in a coin.只要投入硬币，这机器就会给你一份咖啡。② mix and give out (medicines)配（方）；发（药）：Who dispensed the medicine to you?谁给你配的药？
▽dispensation [dispens(e);-ation n.] n.分配；分配物；配方
dispensary [dispens(e);-ary n.] n.配药处；药房
spend [expend或dispense的词头脱落形式→] v.① expend (time)消耗（时间）：He spent three years writing this book.他花三年时间写这本书。② dispense or give out (money) in payment花费（金钱）：How much did you spend on the car?你买这部车花了多少钱？
▽spendable [spend;-able a.] a.可花费的
compensate [com-=together一起；pens=to weigh称；-ate v.=to make使……→“to make one thing weighed together with another so as to make a balance使某物与其他物一起称，以达到平衡”→] v. make a balancing payment for some loss;make up赔偿；补偿：to compensate the workers injured at work赔偿负工伤的工人
▽compensation [compensat(e);-ion n.] n.补偿；赔偿；赔偿费
compensator [compensat(e);-or n.] n.赔偿者；（机器）补偿器
