皮皮学，免费搜题
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搜题
【单选题】
产品质量认证的依据是。A.
质量
B.
协议
C.
法规
D.
标准
拍照语音搜题，微信中搜索"皮皮学"使用
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参考解析：
知识点：
皮皮学刷刷变学霸
举一反三
【单选题】—Can I buy a film ticket? —Oh, sorry, we ___________.
A.
sold them out
B.
sold out them
C.
have sold them out
D.
have sold out them
【单选题】---__________ I have a ticket , please? ---Sorry,sir. All the tickets were sold out ten minutes ago.
A.
May
B.
Need
C.
Must
D.
Should