think / plan ahead (= in advance)
事先考虑/计划
Look ahead when driving.
开车时要看前方。
We were ten points ahead in the basketball game.
在篮球比赛中，我们领先10分。
There were four people ahead of me at the doctor's.
诊所里有四个人排在我前面。
You have a long trip ahead of you.
你前面还有很长的路要走。
The time here is 9 hours ahead of London.
这里的时间比伦敦早9个小时。