– Shall we go and have a picnic at the weekend?– _____ the weather report says there might be a cold front by then.
A:Why not?
B:No, let's not.
C:It depends.
城市道路绿化布置形式多样,“二板三带式”即道路被中间一条绿化带隔离成单向行驶的两条车行道和两条行道树。下图为二板三带式道路绿化断面。人行道上绿化带的作用( )
①涵养水源,减轻内涝
②吸烟滞尘,净化空气
③调节气候,为行人庇荫
④减弱噪音,美化环境
已知3是关于x的方程2x﹣a=1的解,则a的值为( )
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