搜题请搜索小程序“爱下问搜题”
问题 选择题

若正整数a，b，c是一组勾股数，则下列各组数一定还是勾股数的是（　　）

A．a+1，b+1，c+1

B．a2，b2，c2

C．2a，2b，2c

D．a-1，b-1，c-1

答案

根据勾股数的概念知，若有a2+b2=c2，则（2a）2+（2b）2=（2c）2也成立，其它三个不成立，故选C．

单项选择题

临床资料：男，45岁，自述间断性右上腹疼痛1年，进行性加重2月余。

超声综合描述：胆囊形态失常不规则，与周围组织界限不清，内透声不清亮，CDFI：囊壁可见动脉血流信号（箭头所示），V39．9cm／s。见下列彩图。

超声提示（）

A.慢性胆囊炎胆囊泥沙样结石

B.急性胆囊炎胆囊穿孔

C.肝病性胆囊

D.胆囊癌
查看答案
单项选择题

Routing protocols use different techniques for assigning ______ to individual networks. Further, each routing protocol forms a metric aggregation in a different way. Most routing protocols can use multiple paths if the paths have an equal ______ . Some routing protocols can even use multiple paths when paths have an unequal cost. In either case, load ______ can improve overall allocation of network bandwidth. When multiple paths are used, there are several ways to distribute the packets. The two most common mechanisms are per-packet load balancing and per-destination load balancing. Per-packet load balancing distributes the ______ across the possible routes in a manner proportional to the route metrics. Per-destination load balancing distributes packets across the possible routes based on ______.

A. efficiency B. metrics C. utilization D. links
查看答案