A.聽(tīng),摸,聞 B.聽(tīng),看,聞 C.看,磨,擦 D.看,聞,聽(tīng),摸
A.90° B.120° C.150° D.180°
A.清潔,防腐,緊固 B.清潔,防腐,維修 C.防腐,緊固,維修 D.清潔,維修,緊固