Fill in the gaps with a suitable preposition. Write
the correct form of the verb in brackets. Choose the correct word from those
given in brackets.                                The USA is going through a period of fast change.
Today, there are around 3.7 million people aged over 60 in this country but the
large number of people who belong _________________________________ the baby-boom
generation will produce (a/an/the/-_________________________________ explosion
in the number of retired people. By 2030, there (need/might/had to) _________________________________
be some 8.8 million of them. As the birth-rate in the period after the post-war
baby boom has declined sharply, these (elderly/elder/eldest)_________________________________
people will represent a much larger part of the country’s population than ever
before in their history. In 1966, when the US national pension scheme (to introduce)
_________________________________, there were about eight working-age people
for every retired person, whereas today, there are about five, and in 2030 there
will only be three. Recently, another change (already, to take place) _________________________________,
which also affects this situation namely the progresses made in medicine. If it
(not to be) _________________________________ for present medical advances and
higher standards, life expectancy would not increase in future years. For sure,
in 2030, people (to live) _________________________________ an average of 4.5
years longer. Today the US government works on a new retirement policy that is
aimed at (to stop) _________________________________ a financial collapse.

Moreover, this situation made young people (to start) _________________________________
thinking about their parents’ and their own future financial security.