Use the verbs in the brackets in the correct form.
The population of big cities __________ (to increase)
dramatically in recent years. Together with an increase in
population, the number of cars ________ (to grow). It
___________ (to result) in overcrowded roads and pollution.
Urgent measures _________ (to need) to solve these
problems. Over the last few years a number of new
strategies ____________ (to suggest) by urban planners to
improve the situation.