信息系统开发分为若干个阶段,其中建立信息系统总体结构的任务是在下列哪个阶段完成的
A.系统分析
B.系统设计
C.系统实施
D.系统维护
参考答案:C
解析: 参见第40题的解析。
Only at that time ______ that he had made a lot of mistakes in his homework.
A.He realized
B.did he realize
C.he did realized
D.realized he
胃泌素瘤
A.血清胃泌素正常,胃酸正常或降低B.血清胃泌素正常或升高,胃酸正常或降低C.血清胃泌素升高,胃酸显著降低或缺乏D.血清胃泌素升高,胃酸显著增高E.血清胃泌素水平正常或稍高,胃酸高