甘蔗含糖量高，是生产燃料酒精的优质材料．为了提高酒精产量，需要耐高糖和耐酸特性的酵母菌菌种．请回答下面的问题．

－8的立方根是 （   ）

    Mr Brown saw a sweater in a shop window. It was very cheap, so he bought it. When he got home, he put it on. It was all right and he was pleased with it.
   In the afternoon, he went to work in his garden. It soon began to rain and Mr Brown had to run into the house. He ran quickly, but he still got wet. Then his sweater started to shrink(收缩)! It got smaller and smaller. Mr Brown tried to take it off, but he couldn't.
In the end, with the help of his wife, he got out of the sweater. Mrs Brown laughed, “You see, you bought a cheap thing, but…”