He was not prepared to give up that easily. 他可不是个善罢甘休的人。
Don't imagine that they'll behave themselves. They will not take their defeat lying down. 别以为他们会老实的,他们决不会善罢甘休。
牛津高阶第八版
美国韦氏词典
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维基百科 (自由的百科全书)