“仅限货机”标签属于（）。
A.操作标签
B.操控标签
C.危险性标签
D.危险品标签
参考答案：A
—What did you do on May day?
—I went shopping with my family. There ______ so many people in the street. [ ]
A. was
B. are
C. were
D. been
患儿男，10岁。不自主的舞蹈样动作或震颤，语音含糊不清，步态不稳，眼角膜边上形成黄绿色沉积环，可能与下列哪种元素有关（）
A.铁
B.钴
C.铜
D.铬
E.汞
