设M=2a-3b,N=-2a-3b,则M-N=( )
“当前党和人民的主要任务是集中力量发展社会生产力,实现国家工业化,逐步满足人民日益增长的物质和文化需要”。提出这一重要论述的会议是( )
Neil seemed very calm, yet Celia was still aware of his panic _______ the surface.