油机发电机组正常停机时，应先切断（），空载运行（）分钟后再停。
参考答案：负荷；3-5
"His face is round " means _____. [ ]
A. His face is not round.
B. He has a round face.
C. His face likes round
D. He have a round face.
胃溃疡与胃癌的区别，胃癌表现为
A．胃癌溃疡形状不规则，较小
B．底凸凹不平，苔污秽
C．边缘呈结节状起
D．周围皱襞中断
E．胃壁僵硬，蠕动减弱
