要约人确定了承诺期限的要约仍可撤销。( )

相关系数的假设检验，其检测假设H0是（）

A.ρ＞0

B.ρ＜0

C.ρ=0

D.ρ=1

E.ρ≠0

患者男，72岁，因“发热伴腹泻6d，无尿1d，昏迷2h”来诊。查体：BP80/60mmHg；肢端冷。实验室检查：血糖26mmol/L，BUN14mmol/L，血钠156mmol/L，血钾6.2mmol/L，CO₂CP10mmol/L。

对该患者的高钾血症，下列方法中不适当的是（）

A.静脉滴注5%碳酸氢钠溶液

B.立即静脉注射50%葡萄糖溶液60～100ml

C.立即透析

D.静脉注射10%葡萄糖酸钙溶液20～30ml

E.控制感染

F.避免应用血库钾

G.停止含钾饮食和含钾药物

当脱轨车轮离钢轨过远时，应先用（）调正，再使用复轨器。

下列哪项不宜做排泄性尿路造影()

A.骨成骨肉瘤 

B.甲状旁腺功能亢进 

C.骨转移瘤 

D.多发骨髓瘤 

E.骨的尤文氏瘤

Geography is the study of the relationship between people and the land. Geographers compare and contrast various places on the earth. But they also (51) beyond the individual places and consider the earth as a whole. The English word geography means "to describe the earth. " (52) geography books focus on a small area like a town or city. Others deal with a state, a region, a nation, or an (53) continent. Many geography books deal with the whole earth. Another (54) to divide the study of geography is to distinguish between physical geography and cultural geography. The former focuses on the natural world; the (55) starts with human beings and studies how human beings and their environment act (56) each other. But when geography is considered as a single subject, (57) branch can neglect the other. A geographer might be described as one who observes, records, and explains the (58) between places. If all places (59) alike, there would be little need for geographers. We know, however, that no two places are exactly the same. Geography, (60) is a point of view, a special way of looking at place.

56().

A.upon 

B.for 

C.as 

D.to