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.

11.酸是一種化合物，它在溶于水時具有強烈的氣味和對金屬的腐蝕性，并且能夠使某些藍色植物染料變紅。

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

12. Billie Holiday's作為一個爵士布魯斯樂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.

13.理論在本質上是對認識了的現實的一種抽象和符號化的表達。

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

14.兒童在能說或能聽懂語言之前，很久就會通過面部表情和靠發出噪聲來與人交流了。

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

15.受當代灌溉(技術設施)之賜，農作物在原來只有仙人掌和蕎屬科植物才能生存的地方旺盛的生長。

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

16.機械計時器的發展促使人們尋求更精確的日晷，以便校準機械計時器。

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.

17.人類學是一門科學，因為人類學家采用一整套強有力的方法和技術來記錄觀測結果，而這樣記錄下來的觀測結果是供他人核查的。

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

18.真菌在腐化過程中十分重要，而腐化過程將化學物質回饋于土壤，提高其肥力，并分解動物糞便。

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

19.音叉被敲擊時，產生幾乎純質的音調，其音量經久不衰。

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

20.雖然美洲山河桃樹最集中于美國的東南部但是在北至俄亥俄州及伊利諾州也能看見它們。