upset the apple cart

基本解释

Don't try to deal with important issues or make changes that will upset the apple cart.
本周不要处理重要问题或是做出可能会破坏计划的变动；
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It is best not to upset the apple cart if you learn information that may damage a colleague's reputation.
要是你知道了会破坏同事名誉的一些事，最好不要宣扬出去。
"Don't upset the apple cart, " says the bird in this painting, a titmouse, considered an untrustworthy animal in Cherokee lore.
画中的山雀说道：“不要弄翻了这辆苹果车。”在印第安切罗基族人的眼里，山雀是不值得信赖的动物。

On the rare occasions when human rights have upset the apple cart there was usually a pressing need for change.
ECONOMIST: The Human Rights Act has not lived up to expectations. Good
What follows is a back-of-the-envelope view of monthly loan capacity based on what sources see as reasonable assumptions (and no outside shocks to upset the apple cart).
FORBES: Loan Market Technicals Cool In Late September, But Tone Stays Strong