类风湿关节炎的基本病理改变是（）。
A.滑膜炎
B.血管炎
C.类风湿血管炎
D.类风湿结节
E.坏死性小动脉炎
参考答案：A
—How often did Kim eat hamburgers？ —Kim ate hamburgers a week.[ ]
A. one
B. two
C. once
(2012·南京高二检测) Some people are worrying about the possibility _______ mobile phones could be responsible for a range of illnesses, from rashes (皮疹) to brain tumors.
A．that
B．why
C．how
D．whether
