(三)物质的加热(1)用试管夹夹持试管时,应由_________套上、取下.加热固体时,试管口应_____,试管受热时先使_________________,然后用__________________________.
(2)加热液体时,液体体积不超过试管容积的________,加热时使试管与桌面约成____角,为了避免伤人,加热时切不可将试管口______________________________.[来源:学+科+网]
(3)加热后的试管,不能立即____________或_______________.