题目

It’s always awkward when you meet someone from a different country．You never know whether to shake hands, bow or even whether to kiss on the cheek．But what if you were a dog? If you are a dog owner, you must be familiar with how your dog says hello to you．Seconds after you arrive home, your dog jumps up on you．You come face to face with a tail-wagging, wildly excited ball of fur that can’t get enough of you．If you’re not happy with that, it will shower you with wet “kisses” perhaps ruining your best shirt． Like humans, dogs have five senses: smell, touch, sight, he等腰△ABC，一腰AB的垂直平分线交AC于D，已知AB=12，△DBC的周长为20，则BC的长为 [     ]A、6 B、8 C、12 D、14