机采白细胞中,血细胞的比容为()。
A.≥0.28
B.≥0.30
C.≥0.33
D.≥0.35
E.≥0.38
参考答案:C
_____ we have finished the course, we shall start doing more revision work. [ ]
A. For
B. Now that
C. Ever since
D. By now
火车煤的人工采样属于随机采样方法。