用sometimes，sometime，some times或some time完成下面的句子

1.-Will you stay in Beijing for __________?  

    -Yes, I will.

2. __________ he goes to school by bike and __________ by bus.

3. The museum was built __________ before 1258.

4. After __________, Mr Liu came back from abroad.

5. He has been told not to play computer games too much __________.

扩声和音响系统由( )组成。

A．节目源(各类话筒、卡座、CDLD或DVD等)
B．调音台(各声源的混合、分配、调音润色)
C．信号处理设备(周边器材)、功放和扬声器系统等
D．自动管理软件