根据以下材料,回答题Every day 25 million U.S. children fideschool buses. The safety record for these buses is much better than forpassenger cars; but nevertheless, about 10 children are killed each year ridingo
单选题
根据以下材料,回答题Every day 25 million U.S. children fideschool buses. The safety record for these buses is much better than forpassenger cars; but nevertheless, about 10 children are killed each year ridingo