In the room ________ four girls.[ ]
A. is
B. are
C. have
D. has
答案：B
Which of the following statements about sampling errors is FALSE（）
A. Sampling errors are errors due to the wrong sample being selected from the population.
B. Sampling error is the difference between a sample statistic and its corresponding population parameter.
C. Sampling errors will vary from one sample to the next.
API套管钢级标准分类是以套管材质的（）为依据。
A、最小屈服强度
B、最大屈服强度
C、最大上扣扭矩
D、最大抗内压强度
