反映出医学科研的社会性（） A.20世纪50年代西欧研制的药物"反应停"，既可以抑制

某生物兴趣小组调查发现，在黄瓜幼苗期喷洒一次乙烯利溶液(100～200mg·L^-1)，可促进多开雌花，提高黄瓜产量。但乙烯利浓度低于或高于这个范围时，其作用效果尚不清楚。请设计实验，探究乙烯利浓度对黄瓜开雌花数量的影响。

材料用具：2～3片真叶的盆栽黄瓜幼苗若干、乙烯利溶液(300mg·L^-1)、蒸馏水、喷壶…

方法步骤：

(1)将黄瓜幼苗平均分成A、B、C、D四组。

(2)_________________________________。

(3)_________________________________。

(4)连续观察6周，记录并统计_____________________。

(5)实验结果预测：(请在图中将预测的结果以折线的形式表示)

骨样骨瘤典型X线征象是

A．瘤巢及伴有周围硬化

B．好发部位以胫骨、股骨多见

C．很少发生于松质骨，且少见钙化

D．骨膜下者为紧贴骨质的软组织肿块

E．脊椎者多位于附件

车辆倒车时，应（）

A、选好倒车目标.发出倒车信号

B、发出倒车信号.均匀缓慢

C、均匀缓慢

D、选好倒车目标.发出倒车信号.均匀缓慢

用数据传输速率的单位是

A．位/秒

B．字长/秒

C．帧/秒

D．米/秒

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 (71) algorithm. Routingprotocols in internetworks differ slightly from the idealized graph model. In an internetwork, the goal ofthe routers to forward (72) to various networks.
Routers running RIP send their advertisement abOLit cost every (73) seconds. A router also sends an up date message whenever an update from another router causes it to change its routing table.
Routing protocols use different techniques for assigning (74) to individual networks. Further, each routing protocol forms a metric aggregation in a different way. RIP takes the simplestapproach, with all link costs being equal (75) . Thus it always tries to find the minimum hop route. Valid distances are 1 through 15. This also limits RIP to running on fairly small networks.

A．data frames
B．segments
C．packets
D．messages