Sometimes, we see some people reading books while biting their nails (咬指甲). According to the BBC(英国广播公司), up to 45 percent of teenagers bit their nails. There is not an exact answer to{#blank#}1{#/blank#}   why people bite their nails. But most commonly, nail biting is said to be a nervous habit. It is done  {#blank#}2{#/blank#}  of stress(压力), boredom or excitement.

 What's more, a report says that people with higher levels of intelligence(智力)  {#blank#}3{#/blank#}  biting their nails at an early age. It believes that compared  {#blank#}4{#/blank#}  common person,  {#blank#}5{#/blank#}   with higher levels of intelligence may feel higher levels of stress more easily.

 This habit is   {#blank#}6{#/blank#}   for the biters. It can give them red or sore fingertips. And long-term nail biting can affect(影响)   {#blank#}7{#/blank#}   nails grow.

 But don't worry! There are many   {#blank#}8{#/blank#}  to stop biting your nails. First, keep your nails clean. The more you focus on taking care of your nails, the  {#blank#}9{#/blank#}   likely you may bite them again. Also, when you feel stressed, try to relax.  {#blank#}10{#/blank#}  exercise or having a warm bath both help.

      One day, when Bill was  {#blank#}1{#/blank#}   home from school, he heard a noise coming from the bushes（灌木）.He went over to see   {#blank#}2{#/blank#}    it was. Behind a bush, he found a black dog. Bill went back home as soon as he  {#blank#}3{#/blank#}    with the dog and showed her to his parents. Bill's dad found that the dog had a broken leg,   {#blank#}4{#/blank#}  they brought the dog to a doctor for animals by car. On the  {#blank#}5{#/blank#} Bill's parents decided that Bill could keep the dog if they couldn't find the owner.

      When they arrived,the doctor checked the dog. He told  Bill that she {#blank#}6{#/blank#}  going to have babies! The next day, Bill   {#blank#}7{#/blank#}  signs（牌子）like “FOUND DOG BLACK” around his neighborhood. He   {#blank#}8{#/blank#}   wrote his family's phone number on the signs.
    Two days later, Bill got a call  {#blank#}9{#/blank#} the owner of the dog. The owner thanked Bill. When he came to pick up his dog, he said Bill could have    {#blank#}10{#/blank#}  of the babies. Bill was very happy! Finally Bill got a baby dog from the owner. He named him Rosco and liked him very much.

A：Hey, Mark! What happened last night?

B：A man got {#blank#}1{#/blank#}in our neighborhood.

A：What were you doing at that time?

B：I {#blank#}2{#/blank#}a shower.

A：How did you feel when you heard the news?

B：I felt so afraid that I had trouble {#blank#}3{#/blank#} clearly.

A：Did anyone see what happened?

B：No. No one knows the {#blank#}4{#/blank#}.