A2.25M0.5N为井壁取心的电极系，其电极距为（）m。
参考答案：2.5
Asking him for help is ____ because he is such a selfish person.
A．out of the question
B．out of question
C．out of order
D．out of place
如果企业的目标利润为400万元，则该产品出厂价格为( )元/台。
A．3625
B．4250
C．4750
D．4875
