【单选题】已知系统开环传递函数为 ,绘制根轨迹,以下描述正确的是( )。
A.
系统有1支根轨迹,根轨迹的起点为-2,根轨迹的终点为0;
B.
系统有3支根轨迹,根轨迹的起点为-2,根轨迹的终点为0、-1和-4;
C.
系统有3支根轨迹,三支根轨迹的起点分别为0、-1和-4,一支根轨迹的终点为-2,另外2只根轨迹的终点为无穷远;
D.
系统有3支根轨迹,三支根轨迹的起点分别为0、-1和-4,三支根轨迹的终点为-2;
【多选题】A Chinese foreign trade expoter exported 30 000 boxes of goods, contracting to ship the goods in each lot during March to August,5 000 boxes each month, payment by confirmed irrevocable letter of cred...
A.
In order to get payment in due time ,we were supposed to do so.As credit is independent of the contract and once the credit and the relating documents are in conformity ,the exporter can get payment
B.
The letter of credit generally indicate that "the latest date of shipment is 31st,August, by partial shipment",According to UCP 600 section 31A"Unless there are other stipulations, transshipment and partial shipment is allowed".So our exporter was right
C.
in case of trouble in the following days,we shall adopt partial shipment in equal lots,which is corresponding to the contract and letter of credit
D.
Our exporter was wrong. because it is inconsistent with contract
【判断题】每个防火分区应至少设置一个手动火灾报警按钮,从一个防火分区的任何位置到最邻近的一个手动火灾报警按钮的距离不应大于30m。
【简答题】已知负反馈系统的开环传递函数为 (1)试绘制以K为参量的根轨迹图; (2)试求系统处于临界稳定状态时的闭环已知负反馈系统的开环传递函数为 G(s)=K/s(s+2)(s+4) (1)试绘制以K为参量的根轨迹图; (2)试求系统处于临界稳定状态时的闭环极点。
【多选题】在实际测量中,差动变压器式传感器常配用的测量电路主要有( )。
【单选题】What will the woman do at ten o'clock tomorrow?
A.
Meet with a supervisor
D.
Contact the shipping manager
【单选题】党的十八大在建设社会主义核心价值体系的基础上,首次提出了三个“倡导”。在这三个“倡导”中,体现社会层面的价值目标是( )