男性，60岁，以干咳、无力、活动后气促、体重明显减轻6个月入院。体检：呼吸28次／分，两肺底可闻及吸气末期Velcro啰音，有杵状指（趾）。胸部X线：两肺中下野弥漫性网格小结节状浸润影；肺功能示限制性通气障碍和弥散量减少。

该患者最可能的诊断是（）。

A.结节病

B.特发性肺纤维化

C.支气管扩张症

D.肺泡蛋白质沉积症

E.矽肺

Americans are much more likely than citizens of other nations to believe that they live in a meritocracy, i.e. Government by people selected according to merit. But this self-image is a fantasy: America actually stands out as a the advanced country in which it matters most who your parents were, the country in which those born on one of society’s lower rungs have the least chance of climbing to the top or even to the middle.　　And if you ask why America is more class-bound in practice than the rest of the Western world, a large part of the reason is that our government falls down on the job of creating equal opportunity.　　The failure starts early: in America, the holes in the social safety net mean that both low-income mothers and their children are all too likely to suffer from poor nutrition and receive inadequate health care. It continues once children reach school age, where they encounter a system in which the affluent send their kids to good, well-financed public schools or, if they choose, to private schools, while less-advantaged children get a far worse education.