If the population of the Earth keeps on increasing at its present rate, there will eventually not be enough resources {#blank#}1{#/blank#} (leave) to support life on the planet. By the middle of the 26^th century, if present trends continue, we {#blank#}2{#/blank#}（use）up all the oil that drives our cars, for example. Even if scientists develop new ways of feeding the human race, the crowded conditions on the earth will make{#blank#}3{#/blank#} necessary for us to look for open space somewhere else. But {#blank#}4{#/blank#} of the other planets in our solar system are capable of supporting life at present. One possible solution {#blank#}5{#/blank#} the problem, {#blank#}6{#/blank#}, has recently been suggested by an American scientist, Professor Carl Sagan. Sagan believes {#blank#}7{#/blank#} before the Earth's resources are {#blank#}8{#/blank#} (complete) exhausted it will be possible to change the atmosphere of Venus and therefore create a new world almost as large as the Earth {#blank#}9{#/blank#}.The difficulty is that Venus is much hotter than the Earth. {#blank#}10{#/blank#}, there is only a tiny amount of water there.

    Mr. Johnson lived in the woods with his wife and children. He owned{#blank#}1{#/blank#} farm, which looked almost abandoned. {#blank#}2{#/blank#} (lucky), he also had a cow which produced milk every day. He sold or exchanged some of the milk in the towns nearly{#blank#}3{#/blank#} other food and made cheese and butter for the family with what{#blank#}4{#/blank#} (leave). The cow was their only means of support, in fact. One day, the cow was eating grass{#blank#}5{#/blank#} it began to rain heavily. While making great efforts to run away, she{#blank#}6{#/blank#} (fall) over the hill and died. Then the Johnson tried to make a living{#blank#}7{#/blank#} the cow. In order to support his family, Mr. Johnson began to plant herbs and vegetables. Since the plants took a while to grow, he started cutting down trees{#blank#}8{#/blank#}  (sell) the wood. Thinking about his children's clothes, he started growing cotton too. When harvest came around, he was already selling herbs, vegetables and cotton in the market{#blank#}9{#/blank#} people from the town met regularly. Now it occurred to{#blank#}10{#/blank#} that his farm had much potential and that the death of the cow was a bit of luck.

Dear professor Gary,

    I'm {#blank#}1{#/blank#} (terrible) sorry for using the mobile phone in your lecture last week.  I admit {#blank#}2{#/blank#} (make) a mistake and I deserve any {#blank#}3{#/blank#} (punish) for being such a rude student. But I didn't use the mobile phone {#blank#}4{#/blank#} design. I was trying to find a part-time job and that day, a company e-mailed me a job offer and I {#blank#}5{#/blank#} (require) to present my further information without any delay. As {#blank#}6{#/blank#} result, I had to try {#blank#}7{#/blank#} (send) them a text message in class. I promise it will never happen {#blank#}8{#/blank#} me again. But I do need my phone with {#blank#}9{#/blank#} I could communicate with others. I would be grateful {#blank#}10{#/blank#} you could give it to me this time.

    Thank you.

Tom