杠杆率是资本充足率的补充指标，涉及到不同的资产风险时，杠杆率有所不同。

婴儿对食物味道非常敏感，适宜添加辅食的时期是()。

A．1～2个月

B．2～3个月

C．3～4个月

D．4～6个月

E．5～6个月

我国《保险法》规定：“保险活动当事人行使权利、履行义务应当遵循诚实信用原则”，这是因为诚实信用原则在保险活动中具有积极作用。下列说法不正确的是（ ）。

A．诚实信用原则将使保险条款约定不明的问题迎刃而解

B．诚实信用原则有利于规范保险经营

C．诚实信用原则有利于树立良好的保险行业形象

D．诚实信用原则有利于保险合同纠纷的解决

如图为植物呼吸作用的实验装置示意图．请据图回答：

（1）实验中要用黑布遮住大烧杯，其目的是______．

（2）第二天揭开黑布，小烧杯中的石灰水变______了，说明大烧杯内______浓度增加了．

（3）将燃烧的火柴放入大烧杯内，火柴立刻______，说明大烧杯内______浓度大大降低．

（4）如果在烧杯中不放入植株，而放入一只小白鼠，还需用黑布遮盖吗？______．小烧杯中有相同的变化吗？______．

提取生物碱盐不选用的溶剂是

A．酸水
B．甲醇
C．乙醇 D．水
E．氯仿

Networks can be interconnected by different devices. In the physical layer, networks can be connected by (11) or hubs, which just move the bits from one network to an identical network. One layer up we find bridges and switches, which operate at data link layer. They can accept (12) ,examine the MAC address, and forward the frames to a different network while doing minor protocol translation in the process. In the network layer, we have routers that can connect two networks. If two networks have (13) network layer, the router may be able to translate between the packer formats. In the transport layer we find transport gateway, which can interface between two transport connections. Finally, in the application layer, application gateways translate message (14) . As an example, gateways between Internet e-mail and X.400 e-mail must (15) the e-mail message and change various header fields.

12（）

A.frames

B.packets

C.packages

D.cells