most of the children in my time liked to play together under that big tree.___ during the summer holidays

—Have you ___________ been to Beijing? —Yes. But only once.

__________does it cost to go from Shanghai to Beijing?

A smile costs nothing, but gives so ______.

--- ___________ is it from Suzhou to Beijing?--- It used to be a long way, but nowadays, it takes only five hours to get there by high-speed rail.