小兵张嘎的语法难题之四（3）

小兵张嘎

1、
In cold-water habitats,certain invertebrates and fish convert starches into complex carbohydrates called glycerols, (in effect manufacturing its own antifreeze)
c) in effect manufacturing their own antifreeze
D)so that they manufacture their own antifreeze

答案C，请分析一下C、D

2、
According to United States Air Force officials, a cannon （shooting dead chickens at airplanes has proved helpful to demonstrate） what kind of damage can result when jets fly into a flock of large birds.
(A) shooting dead chickens at airplanes has proved helpful to demonstrate
(B) shooting dead chickens at airplanes has proved itself helpful as a demonstration of
(C) shooting dead chickens at airplanes proves itself helpfull as demonstrating
(D) that shoots dead chickens at airplanes proves itself helpful to demonstrate
(E) that shoots dead chickens at airplanes has proved helpful in demonstrating

山峰

gaozi bro

1.   so that前不能有逗号， SO D out!
      For C,  you  may neglect "in effect", thus a typical 现在分词表结果；
2.   "doing", 多次，持续；
    that do, 一次，

good luck

小兵张嘎

1、so that前可以加逗号啊。
2、在机场的确是经常发生的行为。所以我就排出了以that开头的正确答案。郁闷啊！谢谢班主，还望进一步指导。

大浪

1). C is more concise than D.  The meaning is the same in C and D.
2). If use -ing, it means the v-ing happened at the same time as has approved.  This is not logical.  Therefore we need to use -ed