【正文】 diseases and insect pests there are often two kinds of diseases infect rose, powdery mildew and downy powdery mildew often appears in new leaves in early spring and late ’s a kind of spore flow with the water frequently can prevent the the infected leaves must be cut immediately once the rose was downy mildew will hurt the leaves, petals, shoots, humidity should be controlled under 85% to prevent downy mildew and don’t use too much nitrogenous fertilizer to prevent the there are two kinds of insect pests often hurt rose, aphid and red can appear in any time during a will be threaten when weather is should be sprayed in the growing point and back of leaves to control the spider will suck up chlorophyll of pesticide should be sprayed at the early stage of the ：專業(yè)英語演講稿 introduction [?s?:kit]utilizing [?ju:tilaiz] operational 。有了足夠的反饋，閉環(huán)放大器的特點(diǎn)成為一個功能的反饋元件。notation符號 ?= symbol(a)is a buffer [?b?f?] 緩沖器 op工作 amp放大器 ?= symbol(c)is a differential input, differential output op outputs can be thought of as “inverting” [in?v?:t] 反轉(zhuǎn)and “noninverting”, and are shown across from [k?m?pli:??n] 完成of feedback loops on schematics [ski:?m?t?k].符號（a）是一個緩沖器的運(yùn)算放大器 ?=符號（b）是一個差分輸入，單端輸出的運(yùn)算放大器。輸出可以被認(rèn)為是“反轉(zhuǎn)”和“非反相”，并示出從相反的極性的輸入對面容易完成的反饋回路原理圖 power connections電源連接 power is supplied to each of these units at connections as shown in figure a connection is implied in all operational amplifier dual [?dju:?l]兩部分電源供給到這些單元中的每一個，如在圖4中所示的連接。這是通過創(chuàng)建一個浮動的ac地面的隔直流電容器。值，a，是被稱為在運(yùn)算放大器的開環(huán)增益（沒有反饋）。the ideal operational amplifier理想運(yùn)算放大器 in order to introduce operational amplifier circuitry, we will use an ideal model of the operational amplifier to simplify the mathematics [?m?θi?m?tiks] involved in deriving gain expressions, etc., for the circuits this understanding as a basis, it will be convenient to describe the properties of the real devices themselves in later sections, and finally to investigate circuits utilizing practical operational ，我們將使用一個理想的模型簡化中獲得的電路增益表達(dá)式等，所涉及的數(shù)學(xué)運(yùn)算放大器的。defining the ideal operational amplifier ?= gain: the primary function of an amplifier is to amplify, so the more gain the can always be reduced with external circuitry, so we assume gain to be infinite [?infinit]：放大器的主要功能是放大的，所以更多的獲得更好。然后，它可以提供盡可能多的電流所必需的被驅(qū)動的負(fù)載。?= offset: the amplifier output will be zero when a zero signal appears between the inverting and noninverting ：當(dāng)一個零信號之間出現(xiàn)的反相和非反相輸入端，放大器的輸出將為零。如果es承擔(dān)任何非零的值，輸出電壓增大到飽和，該放大器作為一個開關(guān)。輸出鎖存。是啊，腳，我每晚必洗，但從未重視過。我仔細(xì)地洗著腳，漸漸地，我明白了老師的用意：她布置這個特殊的任務(wù)，是為了讓我們認(rèn)識到腳，其實比我們想象的更偉大。我在洗腳，手腳依偎，恍惚間，我仿佛置身于廣袤的大漠中。可大致分為四個部分：學(xué)齡前教育、學(xué)校教育（義務(wù)教育）、延續(xù)教育、高等教育。79年級為一個檔次。其他按照自己興趣，選修三門科目。英國學(xué)生完成GCSE離開學(xué)校后可直接進(jìn)入就業(yè)市場，想升大學(xué)者就會繼續(xù)修讀第六級的Alevel課程。為進(jìn)入高等教育或者就業(yè)打下基礎(chǔ)。Alevel的全稱是“普通教育高級證書”，是學(xué)業(yè)路線的重要階段，學(xué)制一般為兩年。Alevel課程的學(xué)生第一年都將從ASlevel科目開始學(xué)習(xí)，所有學(xué)生必須選修四門以上不同的ASlevel科目。英國的職業(yè)教育與學(xué)業(yè)路線有一定的對應(yīng)性，學(xué)生可以根據(jù)自己的學(xué)業(yè)情況選擇進(jìn)入學(xué)業(yè)路線的不同階段。它的學(xué)習(xí)的方式靈活多樣，學(xué)生可以根據(jù)自己的需要和興趣愛好安排課程，選擇學(xué)分制或模塊式的學(xué)習(xí)方式，甚至可以在學(xué)習(xí)的過程中穿插工作，在學(xué)習(xí)和工作同時進(jìn)行的過程中最終選擇自己最喜歡的事業(yè)。在英國人眼中，醫(yī)科和法律專業(yè)是最難考取也是最難讀的專業(yè)。博士生(Doctorial Degree)高級國家文憑(HNDHigher National Diploma)。進(jìn)入HND要求已經(jīng)完成ALevel或者GNVQAdvanced的課程，中國的高中學(xué)生如果在某些方面（比如計算機(jī)）有特殊專長并且表現(xiàn)出相當(dāng)好的語言能力的話，也有可能直接進(jìn)入HND，但讀起來會相當(dāng)辛苦。大學(xué)每學(xué)年分為了3學(xué)期。對336所大學(xué)院校之申請，皆必須通過UCAS，學(xué)生并不能自己向?qū)W校直接申請。經(jīng)由UCAS需填寫一份申請表(UCAS Form)，表格內(nèi)可填寫6個大學(xué)，亦即最多可同時向六所大學(xué)提出申請，也可以只申請一所大學(xué)。教學(xué)段是第一和第二學(xué)期，第三學(xué)期屬于考試。也就是說，再加一年就可以取得學(xué)士學(xué)位。它是職業(yè)教育體系中的最高階段，學(xué)制一般為兩年。研究生(Master Degree)英國的研究生課程只需要一年時間，這與中國和美國都不同。第四部分：高等教育。GNVQ國家通用職業(yè)文憑。職業(yè)路線。而更像是大學(xué)的基礎(chǔ)課，相當(dāng)于中國大學(xué)本科課程的首兩年。學(xué)業(yè)路線著重于培養(yǎng)學(xué)術(shù)研究方面的人才，職業(yè)路線則結(jié)合社會各層面的職業(yè)需要，培養(yǎng)在各種行業(yè)中具有專門技能知識的人才。16歲到大學(xué)前的教育。所以學(xué)生可以不用為自己之前所不擅長的課再擔(dān)心了。1011年級被稱為GCSE,類似我國的初中。一般是為5歲以下的兒童開設(shè)的，沒有具體的教學(xué)，目的是使他們在讀小學(xué)時更能適應(yīng)學(xué)校生活。第四篇：專業(yè)英語演講稿feet, the carriers of lifegood morning, ladies and would like to tell you about an unusual was surprised and amused when our teacher told us our homework was to wash our feet , washing the feet is such a mon daily activity that i’ve never paid much attention to feet had been cooperating and helping each other, nearly always managing to get washed, while i was enjoying my that night, while i gently touched my feet in the hot water, i realized how nice and cozy bathing my feet could in my mind, the hands always seemed superior to the use all sorts of things from soap to moisture cream to protect their feet bee, kind of, neglected, since the feet spend all day long with the ground and dirt, and quite inevitably, get really i slowly soaped and rinsed my feet, i was beginning to understand why my teacher launched such a wanted us to realize that the feet were more helpful than we had ever , the hands a