一般地说，水电站水道系统经济流速按从大到小次序排列，依次为渠道，有压隧洞和压力钢管。
参考答案：对
He _____ his work with animals.
A．is famous as
B．is famous for
C．is well known as
D．is well known to
夜间手信号红、绿色灯光交互显示数次是溜放信号。
