有下列表现的为：男孩，7岁，常于夜间突发下肢剧痛，有时痛得落泪，疼处无红肿，发热。白天很少有类似情况。随着年龄增长，痛可自行消失。（）

A.风湿性关节炎

B.川崎病

C.紫癜性关节炎

D.类风湿关节多关节炎型

E.生长痛

The primary purpose of the passage is to

(A) indicate some possible technological benefits to the development of new and varied techniques in nanotechnology
(B) argue that science involving the macroscopic tends to be exponentially more difficult than the science of the microscopic
(C) defend the use of the bottom-up approach of building molecules as more efficient relative to the top-down approach
(D) distinguish two different approaches in nanotechnology and comment on their differences and similarities
(E) correct the misconception that the benefits of nanotechnology are likely to be seen in the near future