莱姆病的神经系统病变主要为____和____病变。
参考答案：进行性脑脊髓炎；轴索性脱髓鞘病变
E-mailing is _____ than long-distance calling. [ ]
A. more cheap
B. much cheap
C. more cheaper
D. much cheaper
10KV架空电力线路采用铝铰线时最小允许截面应符合什么要求？
