pull up one's socks打起精神；加緊努力。Pull up your socks！一般是用來提醒小孩子，特別是小男生，因為他們跑來跑去，襪子很容易滑到腳踝。這句對小孩子的叮囑後來就引申為「要對方打起精神，把自己整理好」或「提醒人加緊努力，不要落後」。
看看老外聊天時怎麼用pull up one's socks：
Carl: Is everything all right? You looked exhausted.
Lily: I just wrapped up a major project.
Carl: Why don't you take a day off today?
Lily: Well, I need to pull up my socks for the upcoming event.
Carl: Oh, right. You are in charge of it.
卡爾：沒事吧？你看起來累壞了。莉莉：我剛剛完成了一個大案子。
卡爾：你今天何不請一天假？
莉莉：這個嘛，為了接下來的活動，我必須打起精神。
卡爾：對呀，你是活動的負責人。
pull up one's socks例句精選：
You'd better pull up your socks next term.
下學期你最好加把油。
The new approach requires defence firms to pull up their socks.
新的採購方案使得防務公司們必須打起精神。
If you want to win a sprinting championship, you'll have to pull up your socks.
若你想贏得短跑冠軍就必須鼓足力氣。
There is little the government can do, they should pull up their own socks.
政府幫不了什麼忙，他們要自己加把勁。
Danny：Mom，this is my school report card for this semester.
Mother：Well，it looks like you'd better pull your socks up.
丹尼：媽媽，這是我這學期的成績單。
母親：嗯，看來你最好加緊努力了。
拓展學習：
endeavor 努力
encourage 鼓勵
slacker 偷懶的人
scrutiny 監督
in full force 盡全力；全部
loosen up放輕鬆
trust sb.with sth. 託付某人；重用某人