已知单位反馈系统的开环传递函数为，该系统在单位阶跃输入、单位速度输入和单位加速度输入时的稳态误差为：()

According to the passage, what is most important in solving this awkward problem?A．Reducing the number of the sea lions.B．Recognizing whether the sea lions are the main threats to the salmon.C．Banning the catch of the fish in the Columbia River.D．Forming a good habit of catching fish. 点击查看答案

CAD CAM系统的硬件指()、各种配套外围设备以及各种生产设备等。

A.打印机
B.计算机
C.机床
D.车床

点击查看答案&解析