In my opinion, life in the twenty-first century is much easier than ____.

—Do you think playing cards is beneficial to our study?—No，if ________，it can help us kill time when we have nothing to do.

Shanghai is larger than _____ in Japan.

______of them has been to Australia several times, so they know the Opera House very well.

There is         useful book and         interesting magazine on the desk. They are       my brother’s.