Hi! My name is Ben. I'm 12 years old. I'm very helpful. I usually wash clothes and clean the rooms at home. I always help my teachers at school. And I am a foodie(吃货)，I like ice creams. They are sweet. And potatoes are my favourite vegetables. I like fruits, but I don't like bananas.

    I'm a cool boy，too. I like playing ping-pong，football and I can swim very well. I was afraid of dogs before，but now I have a pet dog. It drinks orange juice every day. It can play with a ball, it's so cute. I like it very much.

    What am I going to be? Mm…I want to be a police officer. Because helping people is fun for me. I will study hard and do more exercise.

以下有甲、乙、丙、丁四组资料
甲：13，15，11，12，15，11，15         乙：6，9，8，7，9，9，8，5，4
丙：5，4，5，7，1，7，8，7，4         丁：17，11，10，9，5，4，4，3
判断哪一组资料的全距最小(  )

废旧手机的某些部件含有Mg、Al、Cu、Ag等金属。为了回收重金属，将旧手机部件浸入足量稀硫酸中充分反应后，过滤，所得固体中含有的金属是（ ）