推进社会主义民主政治制度建设要坚持()的有机统一。下列选项正确的是()
A、依法治国
B、人民当家作主
C、坚持党的领导
D、民主集中
参考答案:A, B, C
— Why does the Lake smell terrible?
— Because large quantities of water _____. [ ]
A. have polluted
B. is being polluted
C. has been polluted
D. have been polluted
多轴飞行器动力系统主要使用()
A.步进电机
B.内转子电机
C.外转子电机