单项选择题

How much Chromium Ⅵ is a safe amount（）

A．No safe level.
B．6 %.
C．It is safe.
D．No one knows.

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单项选择题
Ronald Musoke is a student at （）

A. Uganda College
B. College of Marin
C. Mills College
D. Mudd College
单项选择题
The packing and sorting is being done by（）

A．a moving company
B．College of Matin teachers
C．community volunteers
D．Musoke's college classmates
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