初次交往中，下列哪一种人最容易赢得人们的好感？ [ ] A．非常坦率，甚至不给别

正常产褥期生理变化不包括（）

A.分娩后2～3天乳汁开始分泌

B.产后24小时内T38.5℃

C.产后P60～70次／分

D.子宫体6～8周恢复到正常大小

E.产褥期血白细胞15×10⁹/L

比的前项和后项同时乘或除以非中的数，比值不变．______．

期货交易之所以具有高收益和高风险的特点，是因为它的( )。

A．合约标准化

B．交易集中化

C．双向交易和对冲机制

D．杠杆机制

For each blank, choose the best answer from the four choices and write down on the answer sheet.

(21) is a six bytes OSI layer 2 address which is burned into every networking

device that provides its unique identity for point to point communication.

(22) is a professional organization of individuals in multiple professions which focuses on effort on lower-layer protocols.

(23) functions with two layers of protocols. It can connect networks of different speeds and can be adapted to an environment as it expands.

(24) is the popular LAN developed under the direction of the IEEE802.5.

(25) is the popular backbone technology for transmitting information at high speed with a high level of fault tolerance which is developed under the direction of ANSI.

（24）是（）

A. Ethernet

B. Token Bus

C. Token Ring

D. DQDB

计算动压时需要哪些数据？（）.

A、大气压力和速度

C、空气密度和阻力

C、空气密度和速度

D、空气密度和大气压