[单选题]某企业1月初资产总额为200000元，负债总额为80000元。1月发生下列业务：取得收入共计50000元，发生费用共计30000元，则1月底该企业的所有者权益总额为(　)元。
A.120000
B.100000
C.160000
D.180000

A major reason for (21) in the animal world is territory. The male animal establishes an area. The size of the area is sufficient to provide food for him, his (22) and their offspring. Migrating birds, for example, (23) up the best territory in the order of "first come, first (24) . "The late arrivals may acquire larger territories, but less food is (25) , or they are too close to the (26) of the enemies of the species. (27) there is really insufficient food or the danger is very great, the animal will not mate. In this way, the members of the species which are less fit will not have (28) .
When there is conflict (29) territory, animals will commonly use force, or (30) of force, to decide who will stay and who will go. It is interesting to note, however, that animals seem to use the (31) amount of force necessary to drive away the (32) There is usually no killing. In the case of
A. attack
B. conflict
C. invasion
D. quarrel