词汇运用：（1）从括号中选出恰当的单词填入空白处,使句意完整、明确。
--- Let’s meet ________(in / at) the school gate.
----What about ___________(ride / riding) a bike?
---_______(Is / Does) he dancing in the gym?---No.
--How long can I ________(borrow / keep) the books? ---Two days.
---Are there________(some / any) birds in the tree? ---Yes, there are.