56.In addition to having to be a generalist while specializing in what may seem to be a narrow
field，the researcher is faced with the problem of primary materials that have little or no
documentation.
(what 引导的从句作 specializing in 的宾语)
除了在专攻似乎是一个狭窄领域时不得不成为多面手以外，研究人员还面临着关于原始材料
的文献很少或者根本没有这一问题。
分句 1：in addition to…
分句 2：what may seem …
分句 3：the researcher is…
分句 4：that has little…
1 和 2 嵌套
1 和 3 并列
3 和 4 嵌套
57.Moreover，the degree to which cones are naturally slightly open or tightly closed helps
determine which bill design is the best.
(句子主干是 the degree…helps determine…，从句 to which cones are naturally slightly open or
tightly closed 作 degree 的定语)
而且球果自然地轻微开口或紧紧关闭的程度有助于确定哪种喙的设计是最好的。
Hygiene
58.It was she，a Baltimore printer，who published the first official copies of the Declaration，the
first copies that included the names of its signers and therefore heralded the support of all thirteen
colonies.
(It was…who 为强调句;the first copies 为前面 the first official copies 的同位语)
就是她，一位巴尔的摩的印刷商，出版了《独立宣言》的最早的官方版本，即包括《独立宣
言》签署者名字并因此预告所有 13 个殖民地的支持的早期版本。
分句 1：it was…
分句 2：who publish…
分句 3：the first
1 和 2 嵌套
2 和 3 嵌套
59.By comparison with these familiar yardsticks ， the distances to the galaxies are
incomprehensibly large，but they too are made more manageable by using a time calibration，in
this case the distance that light travels in one year.
与这些熟悉的尺度相比，到太空的距离远得难以理解，但它们也通过使用一个时间的标尺而
变得更加容易对付了，在这种情况下是光在一年内走过的距离。
分句 1：the distance…
分句 2：but they too
分句 3：that…
1 和 2 并列
2 和 3 嵌套
60.The primary reason was skepticism that a railroad built through so challenging and thinly
settled a stretch of desert，mountain，and semiarid plain could pay a profit.
(that 引导的从句作 skepticism 的同位语)
主要原因是存在一种怀疑主义，人们怀疑途经如此富于挑战性、人口稀疏的大片沙漠、山脉
和半干旱平原的一条铁路能否获得利润。
分句 1：the primary…
分句 2：that a railroad…
1 和 2 嵌套