who is standind under the tree?A.Tom is B.Tom does 理由
问题描述：
who is standind under the tree?A.Tom is B.Tom does 理由
答
B，动作，do
答
A Tom is （standind under the tree）。答语省略了。
答
A
因为问句是现在进行时,答语也得是呀
进行时得用am is are