—Tom has never visited the Great Hall of the People, _____?—He went there last month．

He could hardly write his name at the age of 5, ________________?

---He’s never been to an aquarium.---_______.

----“It’s too cold. Would you mind_________ the window?”  ----“_____. But don’t do it now.”

People have cut down many trees every year, so there will be fewer trees, ________?