解方程：2x2+x-2=0（用公式法）

菲德勒的领导理论属于________。

A．伟人论

B．魅力论

C．行为论

D．权变论

对于运行中的绝缘油的闪点应不比新油标准降低（）。

A.5℃

B.10℃

C.15℃

D.20℃

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.

60().

A.still 

B.then 

C.nevertheless 

D.moreover

猫的性别决定是XY型，当体细胞中存在两条或两条以上的X染色体时，只有一条X染色体上的基因能表达，其余X染色体高度螺旋化失活成为巴氏小体，如下图所示。已知猫的毛色黑色对黄色显性，且由位于X染色体上的基因A、a控制。下列说法不正确的是（）

A.可以利用高倍显微镜观察巴氏小体的有无，确定正常猫的性别

B.若出现黑黄相间的雄猫，其基因型可能是XAXaY

C.由该早期胚胎细胞发育而成的猫，其毛色最可能是黑色

D.黄色雌猫与黑色雄猫杂交产生的正常后代，可根据毛色判断其性别

世界园林公认的三大系统是（）

A、东方

B、西亚

C、欧洲

D、古埃及

E、古印度