【单选题】CIDR地址块实际可表示的地址数为()。
【单选题】His father often ______TV in the evening.
【单选题】His father often tells him _______ in that river because it’s dangerous.
【单选题】两个导体球 、 相距很远(可以看成是孤立的),其中 球原来带电, 球不带电。 、 两球半径不等,且 。若用一根细长导线将它们连接起来,则两球所带电量 与 间的关系:( )
【单选题】His father often comes back from work at 10 o’clock at night _______ his mother is waiting for him.
【单选题】His father often helps him _____ his lessons. [ ]
【单选题】Linda with his father often _________ the zoo to see the animal.