Exercise
　　Human beings have distinguished themselves from other animals, and in doing so ensured their survival, by the ability to observe and understand their environment and then either to adapt to that environment or to control and adapt it to their own needs.

　　These expenses , however, usually involve the rent of a small office , expenses for stationary, and possibly , the salary of a secretary.

　　He must assume that you have lived in the tropics , have never seen a coat worn or put on, and that he is to tell you verbally how to do it.

　　要點(diǎn)分析和參考譯文

　　要點(diǎn)：此句為一個(gè)多層次的并列結(jié)構(gòu)，“by” 以前的部分為句子的主體部分，由“and”連接的兩個(gè)并列的分句組成。第二個(gè)分句的主語(yǔ)和一部分謂語(yǔ)省略了以避免重復(fù)。In doing so可以理解為in the process of distinguished themselves from other animals.第二個(gè)分局的完整句子應(yīng)為and in doing so （they have） ensured their survival.By 所引導(dǎo)的短語(yǔ)里ability帶了多個(gè)動(dòng)詞不定式做修飾，這些不定式又存在著一個(gè)并列的結(jié)構(gòu)，to observe and （to） understand與either……or引導(dǎo)的to adapt to……，to control and （to） adapt it……得并列，and連接。
　　參考譯文：人類(lèi)已把自己和其他動(dòng)物區(qū)別開(kāi)了。人類(lèi)具有觀察和了解周?chē)�環(huán)境的能力，能適應(yīng)環(huán)境，控制環(huán)境和根據(jù)自己的需要改造環(huán)境。人類(lèi)就是這樣生存了下來(lái)。

　　要點(diǎn)：在謂語(yǔ)動(dòng)詞involve 后面是由三個(gè)平行的名詞短語(yǔ)構(gòu)成的賓語(yǔ)：he rent of a small office , expenses for stationary, the salary of a secretary.副詞however及possibly 為插入語(yǔ)。
　　參考譯文：然而，這些費(fèi)用通常包括租賃一間小小的辦公室和辦公用品的支出，或許還要包括秘書(shū)的工資。

　　要點(diǎn)：本句中, that 引導(dǎo)的賓語(yǔ)從句共有三個(gè)，have never seen……，是一個(gè)省去了引導(dǎo)詞that及主語(yǔ)you的賓語(yǔ)從句；過(guò)去分詞worn or put on作賓語(yǔ)coat的補(bǔ)語(yǔ)。
參考譯文：他肯定以為，你一直居住在熱帶從來(lái)沒(méi)有見(jiàn)過(guò)穿在身上的外衣或怎樣穿外衣，故而他要告訴你如何穿外衣