掉队

cháng tú xíng jūn jǐ qiān gōng lǐ méi yǒu yī gè rén diào duì

长途行军几千公里，没有一个人掉队。

In a long march of several thousand kilometres, no one dropped out.

bié diào duì

别掉队。

Don't drop behind.

nǐ rú bù gèng jiā nǔ lì de xué xí jiù yào diào duì

你如不更加努力地学习就要掉队。

You'll lag behind unless you study harder.

zài xīn de xíng shì xia yě bù diào duì

在新的形势下也不掉队。

Even under these new conditions, it is not outdated.