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They are simple-minded and easily outwitted, but in large groups can overwhelm the unwary.
它们很单纯,很好骗, 但是一大群则能克服这缺点.
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In intricate subjects, an unseen pitfall can frequently catch the unwary student off guard.
在复杂的学科中，一个不易察觉的陷阱常常会让粗心的学生猝不及防。
金山词霸
