63. Health officials estimate that 35 million Africans are in danger of contracting trypanosomiasis, or "African sleeping sickness," a parasitic disease spread by the bites of tsetse flies.

(A) are in danger of contracting

(B) are in danger to contract

(C) have a danger of contracting

(D) are endangered by contraction

(E) have a danger that they will contract

Choice A, which is both idiomatic and concise, is best. In choice B, to contract is wrong because the phrase are in danger must be followed by of, not by an infinitive. The phrase have a danger is unidiomatic in C. In D, the phrase by contraction trypanosomiasis requires of after contraction; even if this correction were made, though, the passive construction in D would be unnecessarily wordy and also imprecise, because it is the disease more than the act of contracting it that poses the danger. In E, have a danger is again unidiomatic, and the to that clause following the phrase is, within the structure of the sentence, ungrammatical and awkward.

最后一句ungrammatical and awkward 是什么意思啊，我怎么觉得e除了短语用得不对其他没什么问题呢？

不胜感激啊～