下列各项中，加线词语使用恰当的一项是（     ）

If they 　　　　earlier than expected, they 　　　　here now.

Many people can’t learn any lessons from the mistakes they’ve made _____ they get hurt somehow

The government should try to balance economic growth and pollution from industry.—____. It’s time to do it.

l to the Binhai New Area by light railway every day, _____ do manybusinessmen who live in downtown Tianjin.