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【单选题】
为了解新冠病毒肺炎患者预后差的影响因素,对191例患者进行了回顾性队列研究,结果如下表。为比较治疗后生存者和死亡者的淋巴细胞计数(Lymphocyte count, × per L)的差异,请问用何种假设检验方法?A.
生存者和死亡者的淋巴细胞计数变量如果满足正态分布或总体方差，则选用两独立样本的t检验
B.
生存者和死亡者的淋巴细胞计数变量如果满足正态分布且总体方差，则选用两独立样本的t检验
C.
两独立样本率比较的卡方检验
D.
R×C列联表的卡方检验
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【简答题】33 Like many other Gulfport families, the Koshaks quickly began reorganizing their lives, John divided his family in the homes of two friends. The neighbor with her two children went to a refugee cent...
【简答题】对于混合结构多层房屋的流水施工，一般先考虑分部工程的流水，然后再考虑各分部工程之间的相互搭接施工，组成单位工程施工进度计划。
【单选题】有两个电压放大倍数相同、输入和输出电阻不同的放大电路 A 和 B ,对同一个具有内阻的信号源电压进行放大,在负载开路的条件下测得 A 的输出电压小。这说明 A 的 ( ) 。
A.
输入电阻小
B.
输入电阻大
C.
输出电阻大
D.
输出电阻小
【单选题】Terrible as the storm was, umbrellas tightly__________in our hands , we continued our way.A．to ho
A.
34．Terrible as the storm was, umbrellas tightly__________in our hands , we continued our way. A．to hold
B.
holding
C.
were held
D.
held
【简答题】Although anyone can do it, storm chasing is extremely erous. The power of a big storm 31 throw a cow into the air 32 destroy a whole house in seconds. Storm chasers are also often ...
【单选题】[3-34]Above-normal tides near the center of hurricane maybe caused by the ___ .
A.
storm surge
B.
torrential rains
C.
jet stream
D.
high barometric pressure
【单选题】______ the storm, the ship would have reached its destination on time.
A.
But for
B.
In case of
C.
In spite of
D.
Because of
【单选题】INTERTROPICAL CONVERGENCE ZONE OVER SOUTH PHILIPPINE PASSING OVER MINDANAO NORTHERN SULU AND PALAWAN. This paragraph is likely to be under the heading of .
A.
GALE WARNING
B.
24 HOURS FORCAST
C.
SYNOPSIS
D.
STORM WARNING
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