题目内容：
根据上述材料回答题：
The "memory pill", as is mentioned in the first paragraph, is not sold over the counter now mainly because__________.
参考答案：
答案解析：
单选题：根据上述材料回答题：The "memory pill", as is mentioned in the first pa
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- 题目类型：单选题
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The "memory pill", as is mentioned in the first paragraph, is not sold over the counter now mainly because__________.