--      are the Olympic Games held? --Every four years.

 —       did you buy for your mom for Mother’s Day?— Some flowers.

---Did you use to play the guitar? ---        . I’ve never played the guitar.

 —Mr. Wang is in Nanjing for a trip.—Oh, really? When ______ he ______ the trip?

—____ is your schoolbag?—It’s green.