be dumbfounded; be stunned; 吓傻了
act dumb; pretend not to know; 装傻
Don't just keep slogging away. Pay attention to method. 别一个劲儿傻干,要讲究方法。
He didn't come at all. It was silly of us to keep on waiting for him. 他根本没有来,我们傻等了他半天。
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)