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Shoot the breeze 闲扯
When Americans "shoot the breeze," they talk about unimportant things for a long time.
如果美国人shoot the breeze，他们会长时间地说一些鸡毛蒜皮的事情。
This phrase pertains to late-19th-century slang when "breeze" meant "rumor." By the 1910s, the windy word came to mean "empty chatter."这一短语和19世纪末期的一个俚语有关，当时breeze有谣言的意思。到20世纪10年代，breeze的意思就变成了“空谈、废话”。
Ballpark figure 约略的数字
"Ballpark figure" is a sports-related phrase.
No, a "ballpark figure" isn't a synonym for "baseball player." It's actually a financial term referring to a rough numerical estimate.不，ballpark figure不是baseball player（棒球选手）的同义词。实际上，它是一个金融词语，指的是估算出的大概数字。
Sounds like a broken record 一遍又一遍地重复
If someone "sounds like a broken record," they are probably repeating themselves. When a record is broken, it repeats the same line over and over again.
如果某人sounds like a broken record（听起来像一张破唱片），意思是他们在重复自己的观点。一张唱片坏掉时，它会一遍又一遍地重复同一句歌词。
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A bat out of hell 飞速移动的人或物
If someone is moving extremely fast, they are called "a bat out of hell."
如果某人移动得非常迅速，他们就被称为a bat out of hell（来自地狱的蝙蝠）。
People use "a bat out of hell" when someone or something is moving especially fast. Since bats typically like the dark and avoid light, they would fly quickly away from hell that is presumably lit by flames. The saying became so popular that American singer Meat Loaf titled one of his most famous songs "Bat Out of Hell."人们用a bat out of hell来形容飞速移动的人或物。因为蝙蝠喜黑避光，所以它们会飞快地逃离火焰地狱。这一说法非常流行，美国歌手密特·劳弗最著名的一首歌就叫《来自地狱的蝙蝠》。
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It's not rocket science 这很好懂
When something is easy to understand, they might say "it's not rocket science."
如果某事很容易理解，美国人就会说it's not rocket science（这不是火箭科学），意思是这不是高深的事。
This phrase, which gained popularity in the 1980s towards the end of the Cold War, refers to when something isn't that difficult to understand.这个短语是在20世纪80年代冷战末期流行起来的，用来形容那些不难理解的事物。
For the birds 微不足道
If something is trivial or worthless, Americans say it's "for the birds." The phrase was first used as US army slang during World War II.
如果事物微不足道或没有价值，美国人会说这是for the birds（给鸟吃的）。二战期间美军最早开始使用这个俚语。