The physicist rightly dreads precise argument,since an argument that is　convincing only if it is precise loses all its force if the assumptions on　which it is based are slightly changed,whereas an argument that is convincing though imprecise may well be stable under small perturbations of its underlying assumptions. (5+)

物理學(xué)家恐懼于那些精確無(wú)誤的論據(jù)不無(wú)道理，因?yàn)槟撤N只有在它是精確無(wú)誤的條件下才令人置信的論據(jù)，一旦它賴于建立其上的假設(shè)稍有變化，便會(huì)失去它一部的作用;而與此相反，一個(gè)盡管并不精確無(wú)誤但卻令人置信的論據(jù)，在其基本假設(shè)(underlying assumption)稍微受干擾的情況下，仍然有可能是站得住腳的。

難句類型：

復(fù)雜修飾

解釋：

本句在文章中就是一個(gè)自然段，雖然長(zhǎng)度比不上前面第一章中所舉的那個(gè)長(zhǎng)達(dá)10行的例子，但是難度絕不在那句話之下。

本句堪稱句子的大雜燴，連主句帶從句居然一共有八個(gè)。從大往小說，由whereas連接了兩個(gè)大句子，whereas后面的句子中的主語(yǔ)an augument之后又跟了一個(gè)定語(yǔ)從句that is convincing though imprecise, 修飾s前面共有六個(gè)句子，由the physicist作主語(yǔ)的主句;由since引導(dǎo)的原因狀語(yǔ)從句，修飾since從句中主語(yǔ)an augument的由that引導(dǎo)的定語(yǔ)從句，此定語(yǔ)從句中的條件狀語(yǔ)從句only if it is precise; since從句中的條件狀語(yǔ)從句if the assumptions on which it is based are slightly changed,以及修飾此從句中的主語(yǔ)assumptions的定語(yǔ)從句on which it is based一共八個(gè)句子，從句套從句，實(shí)在令人嘆為觀止。

然而，在考試現(xiàn)場(chǎng)去數(shù)句子的數(shù)目，是只有呆子才會(huì)干的事，讀者們惟一要干的事就是反復(fù)閱讀這句話，什么時(shí)候練到不必去想其語(yǔ)法結(jié)構(gòu)就能按原文順序讀懂，才算初步掌握;再進(jìn)一步把它讀順，直到你看不出這個(gè)句子有什么特別的地方，看上去還挺舒服就算訓(xùn)練成功。

意群訓(xùn)練：

The physicist rightly dreads precise argument, since an argument that is convincing only if it is precise loses all its force if the assumptions on which it is based are slightly changed, whereas an argument that is convincing though imprecise may well be stable under small perturbations of its underlying assumptions.