41.C populated = crowed : đông người , đông dân cư

42.B The five most populated cities today are Toky (35 million people) , Mexico City (1 million) , New Yok (`8,5 million),Bombay(18,3 million) and Sou Paulo(18,3 million)

43.D By 2050 there will be 22 citities of that size 

44.A The current population picture is on of dynamic population changes , reflected in a diverse patterns of childbearing , mortality migration , urbanization and ageing .

45.CThe continuation and consequences of these population trend present opportunities as well as challenges for all societies in the twenty-first century