题目内容
【题目】29. In the 1950s in the USA, most families had just one phone at home, and wireless phones _______ yet.
A. haven’t invented B. haven’t been invented
C. hadn’t invented D. hadn’t been invented
【答案】D
【解析】
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题目内容
【题目】29. In the 1950s in the USA, most families had just one phone at home, and wireless phones _______ yet.
A. haven’t invented B. haven’t been invented
C. hadn’t invented D. hadn’t been invented
【答案】D
【解析】
