题目

For their nick-of-time acts, Toby, a 2-year-old dog, and Winnie, a cute cat, were named Dog and Cat of the Year by the American Society for the Prevention of Cruelty to Animals.    As Amy Paul choked(哽住) on a piece of apple at her home, her dog jumped up, landing hard on her chest and forcing the piece in her throat out. When the Keesling family of Indiana was about to be killed by carbon monoxide, their cat clawed at the wife Cathy’s hair until she woke up and called for help. No one could explain their timely heroics. Both pets were rescued by their owners in infancy-----Toby 物理知识渗透于我们生活的方方面面。以下的警示语中涉及到安全用电的是（     ） A．景区水池边立有“水深危险”　　B．输电铁塔下挂有“严禁攀爬”　　 C．汽车的尾部标有“保持车距”　　D．公共场所内标有“禁止吸烟”