"三个同步"原则是指安全生产与经济建设同步规划同步发展同步实施。
参考答案：对
多媒体的应用领域十分广阔，包括______。
A．教育和培训
B．家庭娱乐、休闲
C．商业和服务行业
D．以上三项都包括
—When _______ again?
—When he _______, I'll let you know. [ ]
A. he comes; will come
B. will he come; will come
C. he comes; will come
D. will he come; comes
