矿用热轧槽帮钢分为（）三种型式。
A．B；
B．D；
C．E；
D．M；
E．H。
参考答案：B, C, D
动物按获得途径可分为,先天性行为和___________________。
It ________ over ten years since the dog ____________.
A．is; died
B．is; has been dead
C．has been; has died
D．was; has died
