When ______ and visit our exhibition next month ? -When _______ , I will let you know

I ________ pay Tracy a visit, but I am not sure whether I will have time this Sunday.

Tony’s mom looks young and beautiful.It’s hard to imagine she’s already in her___.

We must not get discouraged ________such a minor setback (挫折)

Chang’e-3 landed on the moon on Dec 14, China became the third country _________ this after the US and the former Soviet Union.