The journey to the airport takes about half an hour.
到机场大约需要半小时。
After half an hour, the fish stopped biting and we moved on.
过了半小时，鱼不再上钩，我们就走开了。
I could stuff myself with ten chocolate bars and half an hour later eat a big meal.
我可以给自己塞下10块巧克力，并在半小时后再大吃一顿。