43．A．growing           B．getting             C．running               D．walking

42．A．arrived            B．grown              C．reached               D．got

41．A．on                B．until               C．before               D．by

40．A．animals            B．plants              C．countries              D．people

39．A．quickly            B．heavily             C．slowly                D．strongly

38．A．thousand           B．million            C．hundred              D．billion

37．A．fast               B．slowly             C．small                 D．big

36．A．From             B．On                C．At                   D．Above

This is a diagram about the population of the world．  36   the diagram we know the population of the world grew quite   37   before 1800．But during the last two   38   years it has grown very   39  ．In 1800, the number of   40   in the word was nine hundred million．But   41   October 12th,1999, the population had   42   six billion．Today, it is still    43   faster than ever before．New research shows that more than 2.6   44   will be born in one    45   in the world．As it goes on, the population of the world   46   seven billion by the year 2010．That   47   we must grow much more food to   48   all the people．Do you know what will   49   in six hundred years? Yes, by then we will have only   50   room on earth．