再求0G: 我的疑惑136,142,154,208,264

OG-136 :

Although schistosomiasis is not often fatal, (it is so debilitating that it has become an economic) drain on many developing countries.

a. (same as above)

C so debilitating is it as to become an econnomic

Answer (a): I can't tell the difference between a and c, sometimes, so as to is better when the subject is consistant and it is the case here except for the order of the words.

OG-142

In one of the most stunning reversals in the history of marketing, the Coca-Cola company in July 1985 yielded to thousands of irate consumers (demanding that it should )bring back the original Coke formula.

b. demanding it to

d who demanded that it

D is correct without doubt, but I try to explain why b is wrong. sb demand sb to do sth is right, but I believe demanding after the noun consumers indicate a action at present. Since the event took place in 1985, demanding is not appropriate with the timing. (am I right?)However, if there is another listed alternative " demanded it to", is it right or even better than d?

OG -154:

In 1791 Robert Carter III, one of the wealthiest plantation owners in Virginia, stunned his family, friends, and neighbors by filing a deed of emancipation, setting free the more than 500 slaves who were legally considered his property.

b setting free more than the 500 slaves legally considered as

the answer is A, and OG explain why b is not good as below:" the misconstructed phrases setting free more than the 500 slaves... mistakenly suggest that Carter set free slaves that were not his own" I just couldn't understand this highlighted sentence. To me, consider as is a wrong phrase, the correct form should be sb consider A B, and that is the reason I exclude b. I don't know if my point is right.

OG-208:

Teratomas are unusual forms of cancer because they are composed of tissues such as tooth and bone not normally found in the organ in which the tumor appears.

E, in that they are composed of tissues such as tooth and bone, tissues

It is said that A changes the meaning of sentence. But I think the sentence is still make sense if choose A.

OG-264:

Scientists believe that unlike the males of most species of moth, the male whistling moths of Nambung, Australia, call female moths to them by the use of acoustical signals, but not olfactory ones, and they attract their mates during the day, rather than at night.

D using acoustical signals, rather than olfactory ones, and attract

The answer is D, my concern here is why by is omitted in D? I think A do sth by doing sth is right.