例1：After the party a few people
stayed behind
to help clean up.
（晚会结束后，⼀些客⼈
留下
来帮助收拾打扫。）
例2：I had
fallen
so far
behind
that it seemed pointless trying to catch up.
（我
落后
太多，似乎追赶下去也毫⽆意义。）