7-6. So was born the echo-sounding apparatus, now in general use in ships.
【譯文】目前船舶上普遍應用的回聲探測儀就是這樣產(chǎn)生的。
【講解】該句是倒裝句。自然語序是The echo-sounding apparatus, now in general use in ships, was so born.這里用倒裝句是為了強調(diào)，也是因為主語太長。now in general use in ships作apparatus的非限制性定語。另請注意，句首的so不是連詞，所以不能譯為“于是”、“因此”，它仍是副詞，作in this way解。這是個倒裝句，如果so是連詞，作therefore解，那就不可能是倒裝句，全句要變?yōu)镾o the echo-sounding apparatus, now in general use in ships, was born。
【單詞和短語】
apparatus：器械；器具；儀器；裝置（the set of tools and machines that you use for a particular scientific, medical, or technical purpose），
例如：
medical apparatus 醫(yī)療器械
7-7. Every solid object will reflect a sound, varying according to the size and nature of the object.
【譯文】凡是固體都反射聲音，反射的聲音因物體體積和質(zhì)地各異而有所區(qū)別。
【講解】varying according to the size and nature of the object作方式狀語，修飾reflect。
7-8. A shoal of fish will do this.
【譯文】魚群亦會反射聲音。
【單詞和短語】
a shoal of fish亦可用a school of fish表達。
7-9. So it is a comparatively simple step from locating the sea bottom to locating a shoal of fish.
【譯文】因此，從測定海底深度到測定魚群的位置這一進展相對較易。
7-10. 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.
【譯文】根據(jù)經(jīng)驗和改進了的儀器，人們不僅能確定魚群的位置，還可以根據(jù)魚群回聲的特點辨別鯡魚、鱈魚還是其他人們熟知的魚種。
【講解】it is now possible…its echo中it是形式主語，not only to locate a shoal but…well-known fish是真正的主語。其中兩個動詞不定式短語由連詞not only…but…連接。if it is herring, cod, or other well-known fish作tell的賓語從句，if意為“是否”。by the pattern of its echo作方式狀語，修飾locate和tell。herring和cod后的逗號用以分隔句中的并列成分。
7-11. It has been found that certain bats emit squeaks and by receiving the echoes, they can locate and steer clear of obstacles—or locate flying insects on which they feed.
【譯文】人們已發(fā)現(xiàn)，某些蝙蝠能發(fā)出尖叫并通過回聲確定并躲開障礙物，或找到它們賴以為生的昆蟲。
【講解】obstacle作locate和steer clear of的賓語。obstacles后的破折號引出被強調(diào)的詞語。they feed指bats feed。
【單詞和短語】
steer clear (of someone/something)：繞開，避開（to avoid sb. or sth. unpleasant or difficult），
例如：
She steered clear of being associated with such people.
她避免與這種人交往。
feed on：以……為食物，吃，食（if an animal feeds on a particular food, it usually eats that food），
例如：
Sheep feed mostly on grass. 羊主要以草食。
Owls feed on mice and other small animals.
貓頭鷹以老鼠和其他小動物為食。
7-12. This echo-location in bats is often compared with radar, the principle of which is similar.
【譯文】蝙蝠這種回聲定位常與雷達相比較，二者原理相似。
【講解】the principle of which is similar是非限制性定語從句。which代表radar。
【譯文】目前船舶上普遍應用的回聲探測儀就是這樣產(chǎn)生的。
【講解】該句是倒裝句。自然語序是The echo-sounding apparatus, now in general use in ships, was so born.這里用倒裝句是為了強調(diào)，也是因為主語太長。now in general use in ships作apparatus的非限制性定語。另請注意，句首的so不是連詞，所以不能譯為“于是”、“因此”，它仍是副詞，作in this way解。這是個倒裝句，如果so是連詞，作therefore解，那就不可能是倒裝句，全句要變?yōu)镾o the echo-sounding apparatus, now in general use in ships, was born。
【單詞和短語】
apparatus：器械；器具；儀器；裝置（the set of tools and machines that you use for a particular scientific, medical, or technical purpose），
例如：
medical apparatus 醫(yī)療器械
7-7. Every solid object will reflect a sound, varying according to the size and nature of the object.
【譯文】凡是固體都反射聲音，反射的聲音因物體體積和質(zhì)地各異而有所區(qū)別。
【講解】varying according to the size and nature of the object作方式狀語，修飾reflect。
7-8. A shoal of fish will do this.
【譯文】魚群亦會反射聲音。
【單詞和短語】
a shoal of fish亦可用a school of fish表達。
7-9. So it is a comparatively simple step from locating the sea bottom to locating a shoal of fish.
【譯文】因此，從測定海底深度到測定魚群的位置這一進展相對較易。
7-10. 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.
【譯文】根據(jù)經(jīng)驗和改進了的儀器，人們不僅能確定魚群的位置，還可以根據(jù)魚群回聲的特點辨別鯡魚、鱈魚還是其他人們熟知的魚種。
【講解】it is now possible…its echo中it是形式主語，not only to locate a shoal but…well-known fish是真正的主語。其中兩個動詞不定式短語由連詞not only…but…連接。if it is herring, cod, or other well-known fish作tell的賓語從句，if意為“是否”。by the pattern of its echo作方式狀語，修飾locate和tell。herring和cod后的逗號用以分隔句中的并列成分。
7-11. It has been found that certain bats emit squeaks and by receiving the echoes, they can locate and steer clear of obstacles—or locate flying insects on which they feed.
【譯文】人們已發(fā)現(xiàn)，某些蝙蝠能發(fā)出尖叫并通過回聲確定并躲開障礙物，或找到它們賴以為生的昆蟲。
【講解】obstacle作locate和steer clear of的賓語。obstacles后的破折號引出被強調(diào)的詞語。they feed指bats feed。
【單詞和短語】
steer clear (of someone/something)：繞開，避開（to avoid sb. or sth. unpleasant or difficult），
例如：
She steered clear of being associated with such people.
她避免與這種人交往。
feed on：以……為食物，吃，食（if an animal feeds on a particular food, it usually eats that food），
例如：
Sheep feed mostly on grass. 羊主要以草食。
Owls feed on mice and other small animals.
貓頭鷹以老鼠和其他小動物為食。
7-12. This echo-location in bats is often compared with radar, the principle of which is similar.
【譯文】蝙蝠這種回聲定位常與雷達相比較，二者原理相似。
【講解】the principle of which is similar是非限制性定語從句。which代表radar。