Complete the gaps with the correct forms of the verbs in brackets. First Conditional If life expectancy increases (increase), people will have to (have to) work longer. 1 The air ___________ (be) cleaner if we ___________ (use) public transport. 2 If unemployment ___________ (go) up, I ___________ (look) for work abroad. 3 Solar panels ___________ (not/work) if the sun ___________ (not/shine). 4 If we ___________ (not/replant) forests, there ___________ (be) less oxygen. 5 We ___________ (not/be able) to drive if there ___________ (not/be) any petrol.