反复出现的上腹部空腹痛，进餐缓解，最可能的疾病是（）
A.食道炎
B.胃溃疡
C.十二指肠溃疡
D.胰腺炎
E.胆囊炎
参考答案：C
The feeling of competition among the students in all the classrooms where the test was going on was noticeable to everyone.
A．discord
B．discovery
C．rivalry
D．cooperation
计费管理的主要目的是控制和______网络操作的费用和代价。
