【单选题】关于电压,下列说法不正确的是( )
C.
电源使正电荷聚集在电源负极,使负电荷聚集在电源正极,从而产生电压
【单选题】If you cancel now you'll _______ all my arrangemen.
【简答题】Company B concluded with Company D an export contract on CIF with L/C payment.The contract stipulated that shipment be made during August, 2006.But the time for the arrival of the L/C was not specifie...
【单选题】All the flats in the building had the same layout.
【单选题】The 'contract' appearing in Paragraph 4 is quite likely referring to______.
A.
an arrangement between USA TODAY and the 'Freedom of Information Act'
B.
a commercial agreement between the Bush administration and Mr. Armstrong Williams
C.
an arrangement between the Education Department and the Ketchum public relations company
D.
a volunteer agreement between Mr. Armstrong Williams and the No Child Left Behind effort
【多选题】关于煤矿供电下列说法正确的是()。
A.
井下负荷属于一级负荷,因而井下应采用双回路供电
B.
为了避免井下电网造成的各种危害,在煤矿井下供电系统中主要采取了过电流保护、漏电保护和保护接地等保护措施
【单选题】关于电压,下列说法不正确的是
C.
电源使正电荷聚集在电源负极,使负电荷聚集在正极,从而产生电压