11. Acids are chemical compounds that, in water solution, have a sharp taste, a corrosive action on metals, and the ability to turn certain blue vegetable dyes red.

　　酸是一種化合物，它在溶于水時(shí)具有強(qiáng)烈的氣味和對(duì)金屬的腐蝕性，并且能夠使某些藍(lán)色植物染料變紅。

　　12. Billie Holiday’s reputation as a great jazz-blues singer rests on her ability to give emotional depth to her songs.

　　Billie Holiday’s作為一個(gè)爵士布魯斯樂(lè)杰出歌手的名聲建立在能夠賦予歌曲感情深度的能力。

　　13. Essentially, a theory is an abstract, symbolic representation of what is conceived to be reality.

　　理論在本質(zhì)上是對(duì)認(rèn)識(shí)了的現(xiàn)實(shí)的一種抽象和符號(hào)化的表達(dá)。

　　14. Long before children are able to speak or understand a language, they communicate through facial expressions and by making noises.

　　兒童在能說(shuō)或能聽(tīng)懂語(yǔ)言之前，很久就會(huì)通過(guò)面部表情和靠發(fā)出噪聲來(lái)與人交流了。

　　15. Thanks to modern irrigation, crops now grow abundantly in areas where once nothing but cacti and sagebrush could live.

　　受當(dāng)代灌溉(技術(shù)設(shè)施)之賜，農(nóng)作物在原來(lái)只有仙人掌和蕎屬科植物才能生存的地方旺盛的生長(zhǎng)。

　　16. The development of mechanical timepieces spurred the search for more accurate sundials with which to regulate them.

　　機(jī)械計(jì)時(shí)器的發(fā)展促使人們尋求更精確的日晷，以便校準(zhǔn)機(jī)械計(jì)時(shí)器。

　　17. Anthropology is a science in that anthropologists use a rigorous set of methods and techniques to document observations that can be checked by others.

　　人類(lèi)學(xué)是一門(mén)科學(xué)，因?yàn)槿祟?lèi)學(xué)家采用一整套強(qiáng)有力的方法和技術(shù)來(lái)記錄觀測(cè)結(jié)果，而這樣記錄下來(lái)的觀測(cè)結(jié)果是供他人核查的。

　　18. Fungi are important in the process of decay, which returns ingredients to the soil, enhances soil fertility, and decomposes animal debris.

　　真菌在腐化過(guò)程中十分重要，而腐化過(guò)程將化學(xué)物質(zhì)回饋于土壤，提高其肥力，并分解動(dòng)物糞便。

　　19. When it is struck, a tuning fork produces an almost pure tone, retaining its pitch over a long period of time.

　　音叉被敲擊時(shí)，產(chǎn)生幾乎純質(zhì)的音調(diào)，其音量經(jīng)久不衰。

　　20. Although pecans are most plentiful in the southeastern part of the United States, they are found as far north as Ohio and Illinois.

　　雖然美洲山河桃樹(shù)最集中于美國(guó)的東南部但是在北至俄亥俄州及伊利諾州也能看見(jiàn)它們。