两个等量正点电荷位于x轴上,关于原点O呈对称分布,下列能正确描述电场强度E随位置x变化规律的图是[ ]
A、
B、
C、
D、
答案:A
The data station usually means a (71) unit that provides data for transmission, that accepts transmitted data, and that performs all functions necessary for communication with another functional unit. Data stations may be divided into two kinds, the primary stations and the secondary stations, (72) control functions.
In (73) data link control, the primary station is the data station that supports the primary control functions of the data link, generates commands to be transmitted, and interprets received responses. Specific responsibilities assigned to the primary station include initialization of control signal interchange, organization of data flow and actions regarding error control and error recovery functions. The secondary station executes data link control functions as (74) by the primary station, interprets received commands and (75) responses to be transmitted.
(72)处填()。
A.helped
B.aided
C.in terms of
D.supporting
技术创新不仅包括产品技术,还包括人才创新。( )