【正文】 el ecti ons 大選之后 The f ormer Pr ime Mini st er, Went wort h Lane, was defeated i n the r ecent elect ions. He is now reti ri ng f rom pol it ical lif e and has gone abroad. My f r iend, Cr awley, has al ways been a f anati cal opponent of Lane39。 he shout ed, Lane was def eat ed in the electi ons. He has reti r ed f r om poli ti cal li f e and gone t o li ve 39。 Lesson84 On st ri ke 罷工 Busmen have decided to go on str ike next week. The st ri ke is due t o begi n on Tuesday. No one knows how long i t wil l last . The busmen have stated t hat t he st ri ke wil l cont inue unt il gener al agr em ent is r eached about pay and worki ng condi tions. Most pe ople beli eve that he str ike wi l last for at least a week. Many owners of pri vat e cars are goi ng to of fer 39。s hom e. We shal al l r emember Page f or hi s patience and under st andi ng and f or the ki ndl y encouragement he gave us when we went so unwil li ngl y to school. A gr eat m any f orm er pupil s wi l be atending a farewel l di nner i n his next Thur sday. It i s a cur ious coincidence t hat t he day bef ore hi s reti rement , Page wi l have been t eaching f or a total of for ty years. Af ter he has r eti red, he wil l devote hi msel f to gar deni ng. For him, t his wi l be an enti rely new hobby. But this does not m at ter , for, as he has oft en remarked, one i s never t oo ol d t o learn. Leson86 Out of contr ol 失控 As the m an tr ied t o swi ng t he speed boat r ound, the st er ingwheel came away i n hi s hands. He waved desper ately t o his panion, who had been wat er ski ing f or t he last fi ft en m inutes. Bot h m en had hardl y had ti me t o reali ze what was happeni ng when the y wer e thr own violent1y into the sea. The speedboat had st ruck a buoy, but it continued t o move very quickl y acr oss t he water. Bot h men had j ust begun t o swim t owar ds the s hore. they noti ced wi th dismay that the speed boat was moving i n a ci rcle. It now came st raight towar ds them at tr emendous speed. In les than a mi nut e, i t roared past them only a few feet away. Af ter it had pased, t hey swam on as qui ckly as t hey could because t hey knew t hat t he boat would soon r eturn. They had just had enough ti me t o swi m out of danger when t he boat agai n pleted a ci rcle. On t his occasion, however , i t had sl owed down consider abl y. Bef or e l ong, the noi se dr opped plet el y and the boat began to dri ft gent ly acr oss t he water. Leson87 A per fect al ibi 極好的不在犯罪現(xiàn)場的證據(jù) 39。Do you al ways catch such an ear ly tr ai n 39。 I m ust be at work at o39。At what t ime di d you ar ive at the stat ion? eight. I bought a paper and wai ted f or t he tr ain.39。 said the i nspect or, 39。 Leson88 Trapped in a m ine 困在礦井里 Si x men have been t rapped in a mine f or seventeen hour s. I f they are not br ought to t he sur f ace soon they may l ose t hei r li ves. However , rescue operat ions are pr ovi ng dif fi cul t. I f explosives are used, vi br ati ons wi l l cause the r oof of the m ine t o colapse. Rescue wor ker s are t her efor e dri l ing a hole on the nort h side of the m ine. They i ntend t o bri ng the men up in a speci al capsul e. I f there had not been a har d layer of rock beneath the soi l, t hey woul d have pl eted the j ob in a few hour s. As it is, they have been dr il li ng for sixteen hours and they sti l have a long way to go. Meanwhile, a m icrophone, whi ch was lowered i nto t he mi ne t wo hours ago, has enabled the m en to keep in touch wi th t he cl osest relat ives. Though they are r unni ng out of f ood and dri nk, the m en ar e cheer ful and conf ident that they wil l get out soon. They have been tol d that rescue operat ions ar e pr ogr esing smoothl y. I f they knew how di f icult i t was to dr il l through t he har d r ock, they would lose hear t. Lesson89 A sli p of the t ongue 口誤 People wi l do anything t o see a fr ee showeven i f it is a bad one. When the news got round t hat a vari ety show woul d be present ed at our local ci nem a by the P. and U. Bir d Seed Company, we al l rushed t o see it . We had t o queue f or hour s to get in and t her e must have been several hundr ed peopl e present just bef ore t he show began. Unfor tunat ely, the show was one of the dull est we have ever seen. Those who fail ed to get i n need not have f elt disappoi nted as many of the ar tist es who should have appeared di d not e. The only f unny things we heard that evening came f rom the adver ti ser at the beginning of t he. He was obviously ve r y ner vous and f or som e minut es stood awkwar dl y befor e the m icrophone. As soon as he opened his m out h, everyone burst out l aughing. We al l know what he poor m an should have sai d, but what he act ual ly said was: This i s Seed Bir d Company. Good l adi es, eveni ng and gent lemen!39。 I l ooked down and near ly fel of f the ladder when I saw a pol iceman. I imm edi at ely r egr et ed answeri ng in the way I did, but I sai d, 39。Excuse m e inter rupti ng you. I hate t o i nt er upt a m an when he39。You see, I 39。 For t unat el y, t he shout i ng woke up m y wi f e who opened t he wi ndow j ust as t he pol i cem an had st ar t ed t o cl i m b t owar ds m e. Lesson93 A nobl e gi f t 崇高的禮物 One of t he m ost f am ous m onum ent s i n t he wor l d, t he St at ue of Li ber t y, was pr esent ed t o t he Uni t ed St at es of Am er i ca i n t he ni eent h cent ur y by t he peopl e of Fr ance . The gr eat st at ue, whi ch was desi gned by t he scul pt or August Bar t hol di , t ook t en year s t o pl et e. The 第 2 頁 共 44 頁 的近似模型，線性化處理后再進行控制，也可以利用非線性控制理論對其進行控制，倒立擺的非線性控制正成為一個研究的熱點。研究者常常是希望通過對倒立擺控制系統(tǒng)的研究獲得性能較為突出的新型控制器設(shè)計方法，并驗證其有效性及控制性能。垂直向下的狀態(tài)是系統(tǒng)穩(wěn)定的平衡點 (考 慮摩擦力的影響 )，而垂直向上的狀態(tài)是系統(tǒng)不穩(wěn)定的平衡點，開環(huán)時微小的擾動都會使系統(tǒng)離開垂直向上的狀態(tài)而進入到垂直向下的狀態(tài)中。 倒立擺系統(tǒng)的分類 倒立擺系統(tǒng)誕生之初為單級直線形式，即僅有的一級擺桿一端自 由，另一端鉸接于可以在直線導(dǎo)軌上自由滑動的小車上。多級擺的擺桿之間屬于自有連接 (即無電動機或其他驅(qū)動