湖泊在下列哪种情况下,湖水含氧量最低[ ]
A.夜间、被污染
B.夜间、未被污染
C.白天、被污染
D.白天、未被污染
答案:C
按照《献血法》的规定,表述错误的是()
A.血站是采集、提供临床用血的机构
B.血站是不以营利为目的的公益性组织
C.血站应当义务无偿为患者提供血液
D.设立血站必须经省级以上人民政府卫生行政部门批准
E.血站的管理办法由国务院卫生厅政府部门制定
Over a very large number of trials, the probability of an event ________ is equal to the probability that it will not occur.
A.occurring
B.to occur
C.occurs
D.occur