战国最为显赫一时的墨家,其深刻的社会根源是[ ]
A.墨子的主张得到人民拥护
B.墨子主张选贤与能,深得天下支持
C.封建经济的发展,小生产者的壮大
D.要求建立小国寡民的社会
答案:C
如图所示,水平放置的弹簧左端固定,小物块P(可视为质点)置于水平桌面上的A点,并与弹簧右端接触,此时弹簧处于原长。现用水平向左的推力将P缓慢地推至B点,此时弹簧的弹性势能为EP=21J。撤去推力后,P沿桌面滑上一个停在光滑水平地面上的长木板Q上,已知P、Q的质量分别为m=2kg、M=4kg,A、B间的距离L1=4m,A距桌子边缘C的距离L2=2m,P与桌面及P与Q间的动摩擦因数都为μ=0.1,g取10m/s2,求:
(1)要使P在长木板Q上不滑出去,长木板至少多长?
(2)若长木板的长度为2.25m,则P滑离木板时,P和Q的速度各为多大?
The Border Gateway Protocol (BGP) is an interautonomous system (71) protocol.The primary function of a BGP speaking system is to exchange network (72) information with other BGP system. This network reachability information includes information on the list of Autonomous System (ASs) that reachability information traverses. BGP-4 provides a new set of mechanisms for supporting (73)interdomain routing. These mechanisms include support for advertising an IP (74) and eliminate the concept of network class within BGP.BGP-4 also introduces mechanisms that allow aggregation of routes, including (75) of AS paths. These changes provide support for the proposed supernettting scheme.
72()
A.secubility
B.reachability
C.capability
D.reliability