A：has been done
B：will have been done
C：had been done
D：is done
We have a good time ____ (practice) ____ (play) softball.
我国户籍制度的改革，取消农业户口与非农业户口的区分，体现了我国的社会主义核心价值观。（ ）
a，b互为相反数，c，d互为倒数，且x的绝对值是4，求x﹣（a+b+cd）+|a+b﹣4|+|2﹣cd|的值．
