审核中抽取的样本应具有代表性，这主要表现为（）。
A、要随机抽样；
B、抽样要具有层次性；
C、抽样应具有均衡性；
D、以上全部。
参考答案：D
A hiker walked for 3 days. She walked 18 miles on the first day, walking 3 miles per hour. On the second day she walked for one less hour, but she walked one mile per hour faster than on the first day. On the third day she walked the same number of hours as on the first day but at the same speed as on the second day. How many miles in total did she walk ？（）
A. 24
B. 44
C. 58
D. 60
E. 62
在补偿贸易业务中，补偿贸易最基本的做法是（）。
A.直接补偿
B.间接补偿
C.劳务补偿
D.其他产品补偿
