But these factors do not account for theinteresting question of how there came to be such a concentration of pregnantichthyosaurs in a particular place very close to their time of giving birth.

　　(Of结构作定语:of howthere came to be such a concentration of pregnant ichthyosaurs...)但这些因素并不能解释这个有趣的问题:为何在一个特定的地点会如此集中地出 现即将临产的怀孕鱼龙群。

　　分句 1:But these factors do not account forthe interesting question

　　分句 2:of how there came to be such aconcentration of pregnant ichthyosaurs in a particular place very close totheir time of giving birth

　　分句 1.嵌套分句

　　2.分句2是Of结构作后置定语修饰说明question 的内容。

　　9.In the seventeenth century the organ,the clavichord,and the harpsichord became the chief instruments of the keyboardgroup,a supremacy they maintained until the piano supplanted them at the end ofthe eighteenth century.

　　(同位语 a supremacy)

　　17世纪时风琴、敲弦琴和拨弦琴成为键盘乐器类的主要成员,这种至高无上的 地位一直由它们保持,直到18世纪末被钢琴所取代。

　　分句 1:In the seventeenth century the organ,the clavichord,and the harpsichord became the chief instruments of the keyboardgroup,

　　分句 2:a supremacy they maintained until thepiano supplanted them at the end of the eighteenth century

　　分句2是分句1的同位语从句,用来修饰说明分句1中的 thechief instruments of the keyboard group

　　10.A series of mechanical improvementscontinuing well into the nineteenth century, including the introduction ofpedals to sustain tone or to soften it, the perfection of a metal frame andsteel wire of the finest quality,finally produced an instrument capable ofmyriad tonal effects from the most delicate harmonies to an almost orchestralfullness of sound,from a liquid,singing tone to a sharp, percussive brilliance.

　　(介词结构 from...to...作定语)

　　持续到19世纪的一系列机械上的改进,包括引入踏板以维持音调或使其柔和, 改善金属框架,以及使用最佳牲能的钢丝,最终产生了一种具备无数音调效果的乐器——这些效果涵盖了从最精致的和声到几乎全部的管弦乐音响,从明快流畅的吟唱音调到尖锐的打击乐器的恢弘气氛。

　　分句 1:A series of mechanical improvementscontinuing well into the nineteenth century

　　分句 2:including the introduction of pedalsto sustain tone or to soften it

　　分句 3:the perfection of a metal frame andsteel wire of the finest quality

　　分句 4:finally produced an instrument capableof myriad tonal effects

　　分句 5:from the most delicate harmonies to analmost orchestral fullness of sound

　　分句 6:from aliquid,singing tone to a sharp, percussive brilliance

　　本句的真正的主句结构其实是由分句1和分句4构成,即A series ofmechanical improvements continuing well into the nineteenth century finallyproduced an instrument capable of myriad tonal effects,,分句2和分句3并列修饰说明分句1中的 A series of mechanical improvements,而分句5和分句6并列,修饰说明了分句4中的 an instrument capable of myriad tonal effects

　　11.The largest later named PuebloBonito(Pretty Town)by the Spanish, rose in five terraced stories,contained morethan 800 rooms,and could have housed a population of 1,000 or more.

　　最大的一座后来被西班牙人称为 Pueblo Bonito(美丽的城镇),是一个五层梯式楼, 有 800 多间房子,能够容纳 1 000 人以上。

　　分句 1:The largest rose in five terracedstories,contained more than 800 rooms, and could have housed a population of1,000 or more

　　分句 2:later named Pueblo Bonito(PrettyTown)by the Spanish

　　分句1嵌套分句2,分句2用来修饰分句1的主语thelargest,分句1内部是由三个并列的谓语构成的句子。

　　13.For a number of years the selection ofmusic for each film program rested entirely in the hands of the conductor orleader of the orchestra,and very often the principal qualification far holdingsuch a position was not skill or taste so much as the ownership of a largepersonal library of musical pieces.

　　(特殊结构 not...SO muchas...——与其说...不如说...) 在好些年内,为各部影片选择配乐的权力完全掌握在乐队指挥或队长手中,而通常担任这种职位的资格与其说是技巧或鉴赏品位,不如说是个人拥有音乐作品的丰富收藏。

　　分句 1:.For a number of years the selectionof music for each film program rested entirely in the hands of the conductor orleader of the orchestra

　　分句 2:and very often theprincipal qualification far holding such a position was not skill or taste somuch as the ownership of a large personal library of musical pieces 分句1和分句2构成并列关系,分句2的难点在于 not...... so much as 的结构。

　　15.The fact that half of the known speciesare thought to inhabit the world's rain forests does not seemsurprising,considering the huge numbers of insects that comprise the bulk ofthe species.

　　(同位语从句 factthat...;定语从句 that comprise the bulk...) 考虑到组成大部分物种的昆虫的巨大数量,认为半数的已知物种栖息在世界的雨 林中这一事实看起来并不令人吃惊。

　　分句 1:The fact does not seem surprising

　　分句 2:that half of the known species arethought to inhabit the world's rain forests

　　分句 3:consideringthe huge numbers of insects

　　分句 4:that comprise the bulk of the species

　　分句 1.嵌套分句

　　2.解释说明分句1的主语thefact,是同位语从句,分句

　　3.作为分句1的原因状语,分句

　　4.是定语从句,修饰

　　分句3的the hugenumbers of insects

　　16.To appreciate fully the diversity andabundance of life in the sea,it helps to think small.

　　(特殊结构 it helpsto...做...有帮助) 要充分认识海洋生命的多样性和丰富性,从小的角度思考有帮助。

　　目的状语:To appreciate fully the diversity andabundance of life in the sea, 主句: it helps to thinksmall.(这里的it是形式主语,没有实际意义)

　　17.Science is built with facts just as ahouse is built with bricks,but a collection of facts cannot be called scienceany more than a pile of bricks can be called a house. (特殊结构 not any more than 像...一样不...) 科学建立在事实上,就像房子用砖砌成一样。但收集的事实不能被叫做科学,就 像一堆砖不能被称为房子一样。

　　分句 1.Science is built with facts just as ahouse is built with bricks,

　　分句 2.but a collection of facts cannot becalled science any more than a pile of bricks can be called a house.

　　1和2是并列分句(转折关系)