A "drop off" sensor underneath the robot prevents it from falling down stairs.

机器人底部安装的一个“防掉落”感应器可以防止机器人从楼梯上摔下来。

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Police said some of the more serious injuries included: a woman in Hirono and another in nearby Aomori City who each broke a leg falling down stairs;

警方说伤势严重者包括：广野町的一位妇女和附近的青森县的一位妇女，她们都在摔下楼梯时摔断了一条腿；

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Last year, a pregnant 22-year-old in Iowa named Christine Taylor ended up in the hospital after falling down a flight of stairs.

去年，爱荷华州一个叫做Christine Taylor的22岁孕妇，在从一段楼梯上跌落下来之后，最终住进了医院。

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Mr Rigby was accused by prosecutor Simon Phillips QC of "trading in lies" in claiming Rio had died after falling down stairs at a house where the defendant was looking after the child.

BBC: Rio Smedley