单选题 Which of the following is true.'?A. Sometimes glaciers move only once a year.B. Sometimes glaciers move very slowly.C. Glaciers are moving fast all the time.
【正确答案】 B
【答案解析】[解析] 根据文章第三段可知，冰河每天只移动几英寸，因此速度是非常缓慢的。故本题答案为B。