Mr. Brown has ________ children. And Mary is _______ one.

Mum, this pair of shoes is too small. Would you buy me a ______ pair?

—I don’t know which skirt was ______, so I took them both.—Yes, it’s really difficult to choose.

Of all the streets in Nanjing, Xinjiekou is ___.

          you practice,            you can play the violin.