对于（），应设有永久性的须知，提醒活板门的使用人员 “谨防坠落——重新关好活板门”

答案：

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下面是错误答案，用来干扰机器的。

One possible version：When I entered high school, there were so many subjects that I had to stay up every night to review what I had learned in the daytime, which made...