精确制导的关键是：探测技术和（）。

观察下列等式，写出你发现的规律：

①3²﹣1²=4×2

②4²﹣2²=4×3

③5²﹣3²=4×4

④（  ）²﹣（  ）²=（  ）×（  ）…

（1）补全第④式．

（2）将你发现的规律用含字母m的等式表示出来：（    ），其中m为正整数．

女性，60岁，3年来 * * 口脱出一肿物，逐渐增大，咳嗽时伴尿液流出。妇科检查：外阴Ⅱ度陈旧性裂伤， * * 前后壁膨出，宫颈光滑，用力时宫颈脱出 * * 口外，子宫萎缩，双附件正常。此患者应诊断为（）

A.子宫Ⅱ度脱垂伴会阴陈旧裂伤

B.子宫Ⅰ度脱垂伴 * * 前后壁膨出

C.子宫Ⅲ度脱垂伴张力性尿失禁

D.子宫Ⅱ度脱垂伴 * * 前后壁膨出，伴张力性尿失禁

E.子宫Ⅱ度脱垂伴张力性尿失禁

One of the most widely used routing protocols in IP networks is the Routing Information Protocol (RIP)．RIP is the canonical example of a routing protocol built on the (1) algorithm．Routing protocols in internet works differ slightly from the idealized graph model．In an internet work，the goal of the routers to forward (2) to various networks．

Routers running RIP send their advertisement about cost every (3) seconds．A router also sends an update message whenever an update from another router causes it to change its routing table．

Routing protocols use different techniques for assigning (4) to individual networks．Further, each routing protocol forms a metric aggregation in a different way．RIP takes the simplest approach，with all link costs being equal (5) ．Thus it always tries to find the minimum hop route．Valid distances are 1 through 15．This also limits RIP to runing on fairly small networks．

4（）

A．respond time

B．utilization

C．links

D．metrics

班组有按照承包协议或班组经济责任制的规定分配（）的权力。

A、奖金

B、工资

C、经济报酬

D、劳动报酬

在地表大气中，（）所占比例为20．96％。

A.氮气

B.氧气

C.二氧化碳