You create an isntance of a BackgroundWorker Component named backgroundworker1.You discover that when the application attempts to cancel the background process you get an exception from the following code segment: backgroundworker1.CancelAsync(); You need to configure the BackgroundWorker component appropriately to prevent to application from exception.What should you do?() Cancel the background process in the backgroundworker1_DoWork event。 Set the IsBusy property og backgroundworker1 to True before you attempt to cancel。 Set the WorkerSupportsCancellation property of backgroundworker1 to true before the code。 Set the DoWorkEventArgs Cancel property to true。
()应作为政府采购的主要采购方式。 A.公开招标 。 B.邀请招标 。 C.竞争性谈判 。 D.单一来源采购。
零库存
电的种类主要有:() 直击雷。 感应雷。 球雷。 雷电侵入波。
()是ABS的控制中枢。
据史料记载,隋文帝开皇四年,智贾租得常田一亩,交与田租银钱五文,租田人不负担田赋;灌田水渠破而水溢,田主不负责。据此可知()。