电网建设进度计划以（）并完成工程结算为终点。
参考答案：项目投产
The United Nations ____ an international organization that tries to find peaceful solutions to
world problems. [ ]
A. is
B. are
C. was
D. were
下述风湿性心脏病二尖瓣狭窄的影像，错误的是（）
A.间质性肺水肿
B.肺门影增大
C.梨形心
D.双房影
E.主动脉结增大
