如何使用导线正弯器整正接触线横弯？

反映企业在一定会计期间的经营成果的会计报表，是指( )。

A．附注
B．现金流量表
C．利润表
D．资产负债表

写出一个只是中心对称图形，但不是轴对称图形的四边形            ．  

不能正确表示条件“两个整型变量A和B之一为0，但不能同时为0”的布尔表达式是( )。

A．A*B=0 and A+B＜＞0

B．(A=0 or B=0)and(A＜＞0 Or B＜＞0)

C．not(A=0 And B=0)and(A=0 or B=0)

D．A*B=0 and (A=0 or B=0)

The network layer provides services to the transport layer. It can be based on either___20___. In both cases, its main job is ___21___ packets from the source to the destination.

In network layer, subnets can easily become congested, ncreasing the delay and ___22___ for packets. Network designers attempt to avoid congestion by proper design. Techniques include___23___ policy, caching, flow control, and more.

The next step beyond just dealing with congestion is to actually try to achieve a promised quality of service. The methods that can be used for this include buffering at the client, traffic shaping, resource___24___, and admission control. Approaches that have been designed for good quality of service include integrated services (including RSVP), differentiated services, and MPLS.

21（）

A. dealing with

B. routing

C. sending

D. receiving

缺少睡眠已经成为影响公共安全的一大隐患。交通部的调查显示，有37%的人说他们曾在方向盘后面打盹或睡着了，因疲劳驾驶而导致的交通事故大约是酒后驾车所导致的交通事故的1.5倍。因此，我们今天需要做的不是加重对酒后驾车的惩罚力度，而是制定与驾驶者睡眠相关的法律。
如果以下陈述为真，哪一项对上述论证的削弱程度最小（）。

A．目前，世界上没有任何一个国家制定了与驾驶者睡眠相关的法律。

B．目前，人们还没有找到能够判定疲劳驾驶的科学标准和法定标准。

C．酒后驾车导致的死亡人数与疲劳驾驶导致的死亡人数几乎持平。

D．加重对酒后驾车的惩罚与制定关于驾驶者睡眠的法律同等重要。