望尘不及 unable to see the dust
Explanation
比喻远远落在后面，无法赶上。
It means to be far behind and unable to catch up.
Origin Story
东汉时期，名臣赵咨因政绩卓著，被朝廷任命为东海太守。临行前，他拜访了老朋友曹暠，曹暠非常敬佩赵咨，便想亲自送他上任。赵咨的车驾飞驰而去，曹暠一路追赶，却始终望尘不及，只能眼睁睁地看着赵咨的车队消失在远方。曹暠感叹道："赵公的才能和功绩，我真是望尘莫及啊！"
During the Eastern Han Dynasty, the famous official Zhao Zi was appointed governor of Donghai due to his outstanding achievements. Before leaving, he visited his old friend Cao Hao, who greatly admired Zhao Zi and wanted to personally see him off. Zhao Zi's carriage sped away, and Cao Hao chased all the way, but he could never catch up, only watching Zhao Zi's motorcade disappear into the distance. Cao Hao sighed, "Zhao Gong's talent and achievements, I really can't compare!"
Usage
形容远远落后，无法赶上。
It is used to describe being far behind and unable to catch up.
Examples
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他的进步速度太快，我们简直望尘不及。
ta de jinbu sudu tai kuai, women ji'an wangchen buji
His progress is too fast, we can't catch up.
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小李的业绩突出，我们都望尘莫及。
xiao li de yeji tuchu, women dou wangchen buji
Xiao Li's achievements are outstanding, we can't keep up