单项选择题
A.20~24℃ B.25~30℃ C.30~35℃ D.35~40℃ E.40~45℃
A.13%~14% B.14%~16% C.17%~18% D.18%~19% E.19%~20%
A.铅 B.甲基汞 C.砷 D.镉 E.铜
A.12%~18% B.<12% C.18%~25% D.25%~33% E.>33%
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