Complete the sentences using conditional 2 and 3 1. if people hadn"t polluted the planet, many species of animals __ (not disappear) 2. if countries __ (spend) more money on scientific research, scientist would have solved some environmental problems 3. if people had dreamed more about space flight, they __ (find) another planet to live on 4. if people __ (use) bicycles more, the air would be much cleaner 5. if i had met tsar ivan, i __ (ask) him not to kill his son