On the north of the bank _____ the Opera House, _____ was built two hundred years ago.

My brother，______ his classmatesoften made fun a few years ago，is now studying in England．

I was about to sail away ______ I heard the sound of stamping and singing on the bank,

________ you play chess—Yes, I can.

It might have_______ your notice but I am very busy at the moment.