下列关于牺牲阳极保护法的优点说法错误的是()。
A.管理简单方便
B.不需要外加电流
C.保护距离长
D.保护作用可靠
参考答案:C
In relation to the law of contract, explain in what circumstances any formalities are required for a valid contract to come into existence. (10 marks)
外用解毒杀虫疗疮;内服补火助阳通便的药物是()
A.雄黄
B.肉苁蓉
C.硫黄
D.白矾
E.蛇床子