比较对象后补足谓语总结一下， do, could or will

SC中比较题还是比较多的，有时候常会不清楚到底补出的谓语是实意动词，还是助动词，请NN帮助总结一下：

885-11

6. The guiding principles of the tax plan released by the Treasury Department could have even a greater significance for the economy than the particulars of the plan.
(A) even a greater significance for the economy than
(B) a significance that is even greater for the economy than
(C) even greater significance for the economy than have
(D) even greater significance for the economy than do
(E) a significance even greater for the economy than have

正确答案是D， 为什么THAN后面不是could 呢？

885-13-22

In its most recent approach, the comet Crommelin passed the Earth at about the same distance and in about the same position, some 25 degrees above the horizon, that Halley's comet will pass the next time it appears.
(A) that Halley's comet will pass
(B) that Halley's comet is to be passing
(C) as Halley's comet
(D) as will Halley's comet
(E) as Halley's comet will do

the key is D

OG-199

199.
                    Because the Earth’s crust is more solid there and thus better able to transmit shock waves, an earthquake of a given magnitude typically devastates an area 100 times greater in the eastern United States than it does in the West.

(A) of a given magnitude typically devastates an area 100 times greater in the eastern United States than it does in the West

(B) of a given magnitude will typically devastate 100 times the area if it occurs in the eastern United States instead of the West

(C) will typically devastate 100 times the area in the eastern United States than one of comparable magnitude occurring in the West

(D) in the eastern United States will typically devastate an area 100 times greater than will a quake of comparable magnitude occurring in the West

(E) that occurs in the eastern United States will typically devastate 100 times more area than if it occurred with comparable magnitude in the West

the key is D

6. The guiding principles of the tax plan released by the Treasury Department could have even a greater significance for the economy than the particulars of the plan.
(A) even a greater significance for the economy than
(B) a significance that is even greater for the economy than
(C) even greater significance for the economy than have
(D) even greater significance for the economy than do
(E) a significance even greater for the economy than have

正确答案是D， 为什么THAN后面不是could 呢？

如果有could的选项应该也可以吧。不过在这道题目里我觉得guiding principle的影响没有particulars of the plan具体、可度量，词义上的细微差别可能是一个用could do一个用do的依据吧。当然，即便这种差别存在，也不那么重要吧。