Dr.Rwagacondo says if children get sick, they don't go to school and fall behind scholastically.

VOA: standard.2009.04.25

you have to like keep working it until... so that you don't fall behind.

你就要不断地工作学习直到……这样你才能不落后。

都是天才 - SpeakingMax英语口语达人

There's a lot of agreement around the need to make sure that electric cars are developed here in the United States, that we don't fall behind other countries.

WHITEHOUSE: Presidential Press Conference

In truth, the other thing pushing parents to send kids to preschool is the cold reality that kindergarten has become the new first grade, with parents pushing academic learning earlier with the fear that their kids will fall behind if they don't meet major milestones like reading well before what is considered normal.

FORBES: The Most Expensive Preschools

You fall too far behind the guys like Pettitte, the good pitchers, they don't make enough mistakes where you can get back at them.

WSJ: Pettitte earns win as Yankees beat Blue Jays 9-4