在离心沉降中球形颗粒的沉降速度（）。A.只与d，ρs，ρ，ut，r有关 B.只与d，

有机化合物的二氯代物有

A．2种

B．3种

C．4种

D．5种

The presentation layer is concerned with the （） and semantics of the informationexchanged between two systems． The processes in two systems are usually exchanginginformation in the form. of character（）,numbers, and so on． The information should be changed to bit（）before ．being transmitted． Because different computers use different encoding systems, the presentation layer is responsible for（）between these different encoding methods． The presentation layer at the sender changes the information from its sender-dependent format into a common format． The presentation layer at the receiving machine changes the common format into its（）dependent format．

Because different computers use different encoding systems, the presentation layer is responsible for（）between these different encoding methods

A．capability

B．interoperability

C．reliability

D．Dependability

监狱人民警察就爱你吃摆事实、讲道理，用理说的方法，对罪犯做耐心细致的说服教育。这所体现的是（）

A.以理服人原则

B.因人施教原则

C.循序渐进原则

D.分类教育原则

激素替代治疗围绝经期综合征的绝对禁忌证有妊娠、原因不明的子宫出血、血栓性静脉炎、胆囊疾病及肝脏疾病。（）

在商业助学贷款中，借款人和自然人保证人的工作单位及通信方式发生变更时，借款人应提前( )天通知贷款银行。

A．10
B．15
C．25
D．30