按要求写出下列化学方程式:(1)丙烯→聚丙烯______;(2)2-溴丙烷→丙烯CH3-CHBr-CH3+NaOH醇加热CH3-CH=CH2↑+NaBr+H2O;CH3-CHBr-CH3+NaOH醇加热CH3-CH=CH2↑+NaBr+H2O;;(3)CaC2→乙炔______.