建设工程项目履行合同的担保形式包括( )。
A．定金
B．抵押
C．保证
D．质押
E．预付金
参考答案：A,B,C,E
The reason why international trade is more costly is that a border typically imposes additional costs such as( )，time costs due to border delays and costs associated with country differences．
A．production
B．tariffs
C．capital
D．goods
在位运算中，操作数每左移一位，其结果相当于
A．操作数乘以2
B．操作数除以2
C．操作数除以4
D．操作数乘以4
