【单选题】—Do you think the rain will stop by noon? — .I want to fly a kite. [ ]
【简答题】磺化反应,一般采用的是() A三氧化硫 B硫酸 C浓硫酸或发烟硫酸 D二氧化硫和三氧化硫
【单选题】采用硫化物沉淀法的原因是,硫化物的( )一般要比其氢氧化物小很多。
【简答题】SBR 一般采用 ( ) 硫化; EPDM 用作汽车门窗密封条时用( ) 硫化,用作耐热输送带时用( ) 硫化。
【单选题】I hope you can study hard and master as much knowledge as possible;otherwise you'll have to live a hard life _____ . [ ]