单词 易碎的固体 例句 DEFINITIVE EXAMPLES 权威例句〔gum〕Any of various viscous substances that are exuded by certain plants and trees and dry into water-soluble, noncrystalline, brittle solids.树胶:某些植物和树木分泌出的一种粘性物质,干燥后成为溶于水的非...