43.Instead of trying to keep down the body temperature deep inside the body, which would
involve the expenditure of water and energy，desert mammals allow their temperatures to rise to
what would normally be fever height，and temperatures as high as 46 degrees Celsius have been
measured in Grant's gazelles.
(what 引导的从句作 rise to 的宾语)
沙漠哺乳动物并不试图将体温控制得很低，因为这么做将会涉及水和能量的消耗，而是允许
体温上升到平常是高烧的温度——有人在格兰特羚羊身上曾测到高达 46 摄氏度的体温。
分句 1：Instead of trying to keep down the body temperature deep inside the body
分句 2：which would involve the expenditure of water and energy
分句 3：desert mammals allow their temperatures to rise to
分句 4：what would normally be fever height
分句 5：and temperatures as high as 46 degrees Celsius have been measured in Grant's gazelles.
分句 3、5 是整个长句子的主句
分句 2 是分句 1 的定语从句
分句 4 是 3 的宾语从句。
1 和 2 嵌套
1、2 和 3 嵌套
3 和 4 嵌套
3、4 和 5 并列
44.Rent control is the system whereby the local government tells building owners how much they
can charge their tenants in rent.
(whereby=by which，引导定语从句，表示手段)
租金管制是政府借以告诉房主他们可以收取多少租金的系统。
分句 1：Rent control is the system
分句 2：whereby the local government tells building owners
分句 3：how much they can charge their tenants in rent.
分句 1 是整个长句子的主句
分句 2 是分句 1 的定语从句，whereby 相当于我们熟悉的 by which
分句 3 是 2 的宾语从句，修饰 tell 的内容宾语(因为 tell 有双宾语)
1 和 2 嵌套
2 和 3 嵌套
45.They were spurred by the inflation of the 1970's，which，combined with California's rapid
population growth，pushed housing prices，as well as rents, to record levels.
(which 引导非限定性定语从句)
它们受到了 20 世纪 70 年代通货膨胀的刺激，这次通货膨胀与加利福尼亚人口的迅速增长结
合在一起，将房价与租金推到了创纪录的水平。
分句 1：They were spurred by the inflation of the 1970's
分句 2：which，combined with California's rapid population growth
分句 3：pushed housing prices，as well as rents, to record levels
分句 1 是整个长句子的主句
分句 2 是分句 1 的定语从句，修饰 inflation
分句 3 同样是分句 1 的定语从句，主语仍然是上一句中的 which
1 和 2、3 嵌套
2 和 3 并列