The major goal of USB was to define an external expansion bus which makes adding (71) to a PC as easy as hooking up a telephone to a wall-jack. USB 2.0 is an evolution of the USB 1.1 (72) , providing a higher performance interface.

A．protocol

B．specification

C．prescript

D．rule

下列哪个因素不是肌张力升高的因素（）

A.骨折

B.气温变化

C.巴氯芬

D.紧张

E.局部肢体受压