20．一I’ll have an examination tomorrow．

   一Really?_________

     A．Sorry to hear that  B．Good luck to you    C．Have a good time    D．Well done

（A）

    People use money to buy food，books，bicycles and hundreds of other things they need. When they work，they usually get paid in money．

    Most of the money used today is made of metal or paper．But in ancient（古代的） time people often used all kinds of things as money．One of the first kinds of money was shells（贝壳）．

    In China，cloth and knives were used as money．Elephant tusks（象牙），monkey tails and salt were used in some pans of Africa（非洲）．Rice was also a kind of money used by the ancient people in some islands．Cows and other animals were used as money，too．

   The first copper coins（铜币）were made in China．They were round and had a square（方形）hole in the centre．Different countries had used different metals for their money．Later sonic countries began to make coins of gold and silver（银）．But gold and silver were heavy to carry when people need a lot of coins to buy something expensive．The Chinese were the first to use paper money．The first paper money looked more like a note from one paper to another than the paper money used today．

19．一Let’s go fishing if it _______this weekend．

    一But nobody knows if it_______ this weekend．

                                                                    A．is fine；will rain        B．will be fine：rains

                                                                    C．is fine；rains D．will be fine：will rain