北朝时期辉煌的石窟艺术与下列哪一现象有直接的关系[ ] A．社会动荡 B．国家统

在中国药典中，通用的测定方法收载在

A．目录部分
B．凡例部分
C．正文部分
D．附录部分
E．索引部分

下列说法正确的包括（）

A．动机是在需要的基础上产生的

B．动机和效果一定是一致的

C．动机是人活动的内部动力

D．不同的活动可以由相同的动机引起

女性，40岁。发现室间隔缺损38年。3个月前拔牙后持续发热至今。查体：体温37.6℃，睑结膜苍白，有瘀点，胸骨左缘第3肋间可闻及全收缩期杂音，脾肋下可触及。最有助于确诊的检查是

A．腹部B超
B．血常规
C．血培养
D．血清铁
E．尿蛋白

Even though current technologies make the ultimate segmented network impractical, new technologies and products hold the promise of making the concept a reality. Most important of all these new technologies are (71) . The ultimate switched LAN, which is technically possible, now, exhibits the following characteristics:
1. High-speed yet cost-effective switching devices can be implemented on a wide scale, providing dedicated connections for individual users and supporting the aggregate (72) of all networked users.
2. The ability to deploy switching capabilities incrementally into the (73) base. Switching implementations support switching of individual users or groups so that existing users of shared media modules can continue to use the existing equipment until they can justify moving to dedicate switched LAN connections.
3. Support and enhancement of existing routed environments. Switching (74) routint, but rather can be introduced into the network without making any changes to the existing routing equipment or configuration. (75) play a critical role in the integration of switching into existing networks.

A. device B. distributedC. installed D. integrated

在没有乳糖的培养基中，（）种E.coli不产生β-半乳糖苷酶。

A、lacI⁺lacP⁺lacO⁺lacZ⁺

B、lacI^-lacP⁺lacO⁺lacZ⁺

C、lacI⁺lacP⁺lacO^clacZ⁺

D、lacI^-lacP⁺lacO^clacZ⁺