Section 4-6,11,12,19

Section 4

19.   To help preserve ancient Egyptian monuments threatened by high water tables, a Swedish engineering firm has proposed installing pumps, perhaps solar powered, to lower the underground water level and dig trenches around the bases of the stone walls.

(A) to lower the underground water level and dig trenches

(B) to lower the underground water level and to dig trenches

(C) to lower the underground water level and digging trenches

(D) that lower the underground water level and that trenches be dug（C）

(E) that lower the underground water level and trench digging

C中间digging是和installing平行的，但我感觉C选项and之前少了一个逗号。

我严重同意楼主的说法，其他几题建议楼主去讨论区看看，都有的。

12.   Most nations regard their airspace as extending upward as high as an aircraft can fly; no specific altitude, however, has been officially recognized as a boundary.

(A) as extending

(B) as the extent

(C) to be an extent

(D) to be an extension（A）

(E) to extend

这题大家怎么看，我觉得选B比较合适，regard something as something；把airspace视为extent[范围]要比把airspace视为extending这个动作要好吧；后面是省略表达the extent （which is） upward；是不是说这里B的“the”不漂亮才不选B呢？

11.   Several studies have found that the coronary patients who exercise most actively have half or less than half the chance of dying of a heart attack as those who are sedentary.

(A) have half or less than half the chance of dying of a heart attack as those who are sedentary

(B) have half the chance, or less, of dying of a heart attack than those who are sedentary do

(C) have half the chance that they will die of a heart attack, or less, than those who are sedentary do

(D) are at least fifty percent less likely to die of a heart attack as those who are sedentary（E）

(E) are at least fifty percent less likely than those who are sedentary to die of a heart attack

这道题目怎么解，哪位朋友给我讲讲呢。

6.     Because young children do not organize their attention or perceptions systematically, like adults, they may notice and remember details that their elders ignore.

(A) like adults

(B) unlike an adult

(C) as adults

(D) as adults do（D）

(E) as an adult

这道题目怎么翻译？