How many birds can you see in the tree?注意: in the tree 是外来物在树上;如松鼠、鸟、蝴蝶等;on the tree 是指树上原有的原生物,如果实、花儿等;相关单词和短语:1、看见:see;seeing;catch;sight of;the vision of;2、多少:number;amount;somewhat;more or less;how many;how much.