like a red rag to a bullBritish EnglishBrE (also like waving a red flag in front of a bull American EnglishAmE)ANGRYUPSET very likely to make someone angry or upset 容易使人愤怒；容易使人苦恼 Just mentioning his ex-wife’s name was like a red rag to a bull. 只要提到他前妻的名字，他就会怒不可遏。
like a red rag to a bull• Naturally this was like a red rag to a bull and I refused to even consider such a course of action.
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