When Alice was sixteen, I was the one who wanted to run away from home. It was 1 to see the changes coming over her. She skipped school, and refused to communicate. I tried being firm, but it didn‘t 2. I saw a dark future for my once sweet daughter.

    One school day Alice returned home very late. With a quarrel in view. I was surprised to see Alice was 3.

     “I hope I did the right thing, Mom,”“Alice said. I saw a cat, all bloody but alive. I 4it to the vet's(宠物医院), and was asked to make payment 5. As I couldn't reach anyone at the phone number on the cat's tag(标牌), I had to pay the bill.”

    In the following days, the owner still couldn't be 6. Alice paid the vet to continue treatment. I grew 7: what if the family had simply left the cat behind?

    A week went by. A woman called to speak to Alice.

    “She is at school,” I said.

    “You have a 8daughter,” she said, apparently in tears.

    Her family had just returned from abroad, and got a (n) 9 from the vet. Their cat was recovering, thanks to Alice's 10. “We can't wait to hug Cuddles again,” she sobbed.

    Upon her return home, Alice was filled with 11at the news. So was I. I learned through another woman's eyes that my daughter was still a good person despite her 12teenage years. Her warm heart would surely guide her in the right direction.

设函数$f\left(x\right)=\left(x^2-8x+c_1\right)\left(x^2-8x+c_2\right)\left(x^2-8x+c_3\right)\left(x^2-8x+c_4\right)$，集合$M=\left\{x|f\left(x\right)=0\right\}=\left\{x_1,x_2,\cdots ,x_7\right\}$$\subseteq N^{*}$，设$c_1\ge c_2\ge c_3\ge c_4$，则$c_1-c_4=$(    ）

— What’s your English teacher like?

—To a certain degree, she is serious but helpful.