适用于松砂、粉土、杂填土及湿陷性黄土的路基处理方法是（）。
A.换土垫层
B.排水固结
C.振密
D.碾压及夯实
参考答案：C
The duty-paying value shall be ______.
A．the value of imports or exports declared by the consignors or consignees
B．the true transaction value of imports & exports
C．the value higher than the transaction value of identical or similar goods
D．the value lower than the transaction value of identical or similar goods
给水排水管道的埋设深度应根据土壤冰冻深度，管内介质温度，管道外部荷载、管经、管材及管道交叉等因素确定，一般规定有哪些？
