1.Not all sounds made by animals serve as language, and we have only to turn to that extraordinary discovery of echo-location in bats to see a case in which the voice plays a strictly utilitarian role.
not all 部分否定
play a role 扮演角色，发挥作用
例句：Biological factors play a major role in the development of mental illness.
生物因素在精神疾病的发展过程中起着很重要作用。
turn to 求助于，转到
例句：When you come across some difficulies,you must turn to a policeman for help.
遇到问题时，必须向警察求助。
2.The further off this solid obstruction, the longer time will elapse for the return of the echo.
the比较级表示越……越……
例句：The higher you climber,the more difficult it's for you to breath.
爬得越高，越难呼吸。
3.Every solid object will reflect a sound, varying according to the size and nature of the object.
according to 根据，按照
例句：According to the color, I would say that this jacket belongs to those trousers.
按颜色来说呢，我觉得这件夹克和那条裤子很配。
4.With experience, and with improved apparatus, it is now possible not only to locate a shoal but to tell if it is herring, cod, or other well-known fish, by the pattern of its echo.
not only,but
例句：not only，but also 不但，而且，连接两个并列的成分。而且有时also可以省略。例句：They not only broke into his office and stole his books,but also tore up his manuscripts. 他们不仅闯进他的办公室，偷走了他的书，而且还撕掉了他的手稿。
5.This echo-location in bats is often compared with radar, the principle of which is similar.
compare with可与……相匹敌；可与……相比；与……比较（异同）
例句：Her garden can't compare with ours.
她的花园没法和我们的相比。
We are in a developing country, so don't compare us with developed countries in terms of material life.
咱是发展中国家，物质生活方面别跟发达国家攀比。
