og 15 perhaps與may be的差別

In his research paper, Dr. Frosh, medical director of the Payne Whitney Clinic, distinguishes mood swings. which may be violent without their being grounded in mental disease, from genuine manic-depressive psychosis.

(A)  mood swings, which may be violent without their being grounded in mental disease, from genuine manic-depressive psychosis

(B)  mood swings, perhaps violent without being grounded in mental disease, and genuine manic-depressive psychosis ,

(C)  between mood swings, which may be violent without being grounded in mental disease, and genuine manic-depressive psychosis

(D)  between mood swings, perhaps violent without being grounded in mental disease, from genuine manic-depressive psychosis

(E)   genuine manic-depressive psychosis and mood swings, which may be violent without being grounded in mental disease

the modifier of mood swings in B and D (perhaps violent) is awkward and less clear than the more developed clause which may be violent.  perhaps與may be的問題好像在之前都沒解決,難道真的就是ETS不喜歡perhaps就都不用嗎?? 有沒有其他的解釋呢?

may be

1, possible. (可能）

2, it's going to be.（可以是）

just my 2 cents.

og11-2 Of all the vast tides of migration that have swept through history, maybe none is more concentrated as the wave that brought 12 million immigrants onto American shores in little more than three decades.

(A) maybe none is more concentrated as

(B) it may be that none is more concentrated as

(C) perhaps it is none that is more concentrated than

(D) maybe it is none that was more concentrated than

(E) perhaps none was more concentrated than

This sentence depends on the comparative structure x is more than y. Here, an idiomatically incorrect construction x (none) is more as y (the wave) is used. In addition, the second part of the sentence uses the past tense verb brought, indicating that the event is over. The verb used in the comparative construction must also be past tense, x (none) was more concentrated than y (the wave). Maybe and perhaps are interchangeable; perhaps is slightly more formal.

A     Incorrect idiom is used for comparison; is concentrated is the wrong tense

B     Incorrect idiom is used for comparison; it may be that is wordy

C     It is none that is more ... is a wordy and ungrammatical construction

D     It is none that was more ... is a wordy and ungrammatical construction

E     Correct. The correct comparative construction is used in this sentence; the verb is past tense.

The correct answer is E.

把这个问题顶起来，我也碰到了。这里是不是并没有强调perhaps 和 may be的区别，而是在说，定语从句要比插入语更clear呢？