老年性痴呆的病理特征是（）
A.大脑皮质萎缩
B.小脑脑沟增宽
C.老年斑和神经元纤维缠结
D.脑室扩大
E.神经元气球样肿胀
参考答案：C
You must be careful when ___ on the highway.
A．you driving
B．are driving
C．driving
D．you were driving
