When entering from seaward,a buoy displaying a single-flashing red light would indicate ().
A. a junction with the preferred channel to the left
B. a sharp turn in the channel to the right
C. the starboard side of the channel
D. a wreck to be left on the vessel's port side
You are creating a Windows Forms application for a financial service provider by using the .NET Framework 3.5. You have to implement a multiple document interface (MDI) in the application to allow users to open multiple financial documents simultaneously.You need to ensure that whenever the child MDI form is created, the application displays a message in the title bar of the parent MDI that a child form has received focus. What should you do?()
A. Implement theActivated event
B. Implement the MdiChildActivate event
C. Override the OnParentVisibleChanged method
D. Override the OnParentBindingContextChanged method
相对密度是指在给定的温度下一物体的密度与特定温度下纯水密度的比值。()
A. 正确
B. 错误
当在试验机A上进行测量时,测量结果总是偏高,因此我们说这台试验机的()大。
A. 偶然误差
B. 系统误差
C. 标准偏差