A poor farmer had a friend,who was famous for the wonderful apple he grew.One day,his friend gave the farmer a young apple tree and told him____(take) it home and plant it.

    The farmer was pleased with the gift,but when he got home he did not know where to plant it.He was afraid that ____he planted the tree in one of his fields,his neighbors would come at night and pick some of the apples.Finally he planted the tree in his wood____no one could see it.But____sunlight and good soil,the tree soon died.

    Later the friend asked the farmer why he had planted the tree in____a poor place."What's the difference?"the farmer said____(angry)."If I had planted the tree near the road,strangers____(steal) the fruit."

    "Yes,"said the friend,"____at least someone could have enjoyed the fruit.Now you not only have robbed everyone____the fruit,but also you____(destroy)a good apple tree!"

有关专家提出了“以废治废”的治理污染新思路，并且起到了一定的成效．如冶炼钢铁时，为减少煤中硫燃烧生成的二氧化硫所造成的污染，一般是在煤燃烧时添加生石灰或石灰石进行固硫（主要是利用氧化钙与二氧化硫反应生成亚硫酸钙）． 根据这一原理，有人将造纸厂回收的碱白泥（主要成份：CaCO₃和NaOH）掺进煤中进行固硫．用碱白泥固硫时，下列说法不正确的是（    ）

①S+O₂ SO₂                      

②CaCO₃ CaO+CO₂↑

③CaCO₃+2NaOH═Na₂CO₃+Ca（OH）₂

④SO₂+CaO CaSO₃

⑤SO₂+2NaOH═Na₂SO₃+H₂O．