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
参考答案：A
解析：
根据句意，本句讲述的是人与环境之间的相互影响，而动词act后可以与on或upon连用，意为“对……起作用”，符合本句的意思。act for意为“代理(某人职务)”．act as意为“充当；起作用”，act to不能固定搭配使用。