Efficiency and redundancy are contradictory characteristics of linguistic systems; however, they can be used together to achieve usefulness and reliability in communication. If a spoken language is completely efficient, then every possible permutation of its basic language rounds can be an understandable word. However, if the human auditory system is an imperfect receptor of sounds, then it is not true that every possible permutation of a spoken language’s basic language sounds can be an understandable word.
If all of the statements above are true, which one of the following must also be true

A．Efficiency causes a spoken language to be useful and redundancy causes it to be reliable.

B．Neither efficiency nor redundancy can be completely achieved in spoken language.

C．If a spoken language were completely redundant, then it could not be useful.

D．If the human auditory system were a perfect receptor of sounds, then every permutation of language sounds would be an understandable word.

E．(E) If the human auditory system is an imperfect receptor of sounds, then a spoken language cannot be completely efficient.

女性，32岁。因支气管扩张行左下肺叶切除术，术后半年再次出现反复咯血。在分析其复发的原因时，下列不考虑的是（）。

A.病灶切除不足够或定位不准确，残留部分支气管扩张的病肺

B.肺切除时支气管残端保留过长或残端缝线周围有慢性肉芽肿

C.左上肺叶支气管发生移位或扭曲致引流不畅

D.凝血功能障碍

E.术后的并发症，如脓胸、支气管胸膜瘘等未能及时治愈