【单选题】【消耗次数：1】
下面这些材料的逸出功为：铍，3.9eV；钯，5.0eV；铯，1.9eV；钨，4.5eV.要制造能在可见光（频率范围为3.9×1014Hz－7.5×1014Hz）下工作的光电管，在这此材料中应选：（）。
①
钨
②
钯
③
铯
④
铍
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