Choose the correct verb form, a or b, to complete each sentence.
1 Unless we … flying, we won’t reduce global warming.
a stop b will stop
2 Unless we … the way we travel, we will have serious environmental problems.
a change b will change
3 If you pay to offset carbon emissions, you … better.
a feel b will feel
4 Is it OK for me to fly if I … an organization which funds carbon offset projects?
a pay b will pay
5 The situation … better unless we do something immediately.
a gets b won’t get
6 If we don’t travel so much, we … carbon emissions.
a reduce b will reduce