根据题意得：2x≥02x-1≠0，
解得：x≥0且x≠12．
故选B．
During the war there was a serious lack of food. It was not unusual that even the wealthy families had to ______ bread for days.
A．eat up
B．give away
C．do without
D．deal with
网内往来系统收到的查询，按（）时间顺序专夹保管。
A.发出查询
B.收到查询
C.发出查复
D.以上答案均不对
