Green sea turtles are reptiles (爬行动物). They are {#blank#}1{#/blank#} (find) throughout the world's seas. They are probably the oldest animals {#blank#}2{#/blank#}the Earth. Their ancestors(祖先) used to walk on land, and then went back {#blank#}3{#/blank#}the sea many million years ago. They watched dinosaurs go missing. Although they are endangered animals, the number of them is{#blank#}4{#/blank#}(rise). Green sea turtles are cold-blooded and they breathe air. They each have a hard shell like nearly all turtles. Many land turtles are able to take their heads back into their shells for {#blank#}5{#/blank#}(protect). Green sea turtles cannot do this, and their heads will be out at all times. Their shells are {#blank#}6{#/blank#}(light) in weight than those which live on land. When green sea turtles swim, they will come out of the sea every few {#blank#}7{#/blank#} (minute) to take a breath.{#blank#}8{#/blank#} when they sleep, they can remain in water for two hours without taking a breath. Green sea turtles seem to grow very {#blank#}9{#/blank#} (slow). Adult green sea turtles can weigh about 500 pounds. Green sea turtles live in the ocean {#blank#}10{#/blank#} most of their adult lives.

    The whole school was talking about the winter camp. And everyone was looking forward{#blank#}1{#/blank#}it except me because I thought I would get homesick. But it was the way we grew up.

    When arriving at the camp, we {#blank#}2{#/blank#}(ask)to ski(滑雪)down to a field by the coach. I skied{#blank#}3{#/blank#}(careful), but I still hit a piece of ice and fell down.

     "Ha！Ha!" Behind me, somebody started laughing. I looked back to see{#blank#}4{#/blank#}(whom)was laughing at me. To my surprise, I saw {#blank#}5{#/blank#}girl in the same embarrassing(令人尴尬的)position I was in. "I thought I'd be bad at this, but it seems{#blank#}6{#/blank#}(difficult)than I expected!" she said. Suddenly, I started laughing, too. After being so afraid of{#blank#}7{#/blank#}(fall), it was a comfort not to fear it anymore.

    The next day, {#blank#}8{#/blank#} I didn't want to go ski jumping, I was chosen to do that first. But when my{#blank#}9{#/blank#}(foot)left the ground, I felt I was flying and it was wonderful.

    Just do your best {#blank#}10{#/blank#}(meet)every challenge(挑战).You'll never imagine how much you will get.