Choose the best answer: If people ..... public transport, there will be less pollution

I, Choose the best answer
1, If people ............ public transport, there will be less pollution.
A. use B.will use C.cam use D. used
2............ we miss the last bus, we will have to walk home.
A.As B.When C.If D.Unless
3.People have ........ this beach with a lot of trash.
A.spoiled B.cleaned C.collected D.protected
4.He got a ............. for parking on double yellow lines.
A.fee B.ticket C.fine D.token
5.By sicking labels oves thr address you can.......... envelopes.
A.recycle B.reduce C.reuse D.return
6. Because plastic bags are very hard to .............., they will cause pollution
A.dissolve B. wrap C.tear D.collect