The author believes that our knowledge of social systems is more secure than that of physical systems because ______.

A:it is not based on personal experience B:new discoveries are less likely to occur in social sciences C:it is based on a fairly representative quantity of data D:the records of social systems are more reliable

The presentation layer is concerned with the（1） and semantics of the information exchanged between two systems. The processes in two systems are usually exchanginginformation in the form of character（2）numbers, and so on. The information should bechanged to bit （3） before being transmitted. Because different encoding systems, thepresentation layer is responsible for （4）between these different encoding methods. Thepresentation layer at the sender changes the information from its sender-dependent format into acommon format. The presentation layer at the receiving machine changes the common format intoits （5） dependent format.

A:systems B:characters C:layers D:streams

The presentation layer is concerned with the (1) and semantics of the information exchanged between two systems. The processes in two systems are usually exchanging information in the form of character(2), numbers, and so on. The information should be changed to bit (3) before being transmitted. Because different computers use different encoding systems, the presentation layer is responsible for(4) 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(5)-dependent format.

A:systems B:characters C:layers D:streams

The presentation layer is concerned with the （）and semantics of the information exchanged between two systems. The processes in two systems are usually exchanging information 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.

A:systems B:characters C:layers D:streams

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．
 

The information should be changed to bit（）before ．being transmitted

A:systems B:characters C:layers D:Streams

For users, microkernel technology promises (90) , compact and sophisticated operating systems that are typically (91) across a range of hardware platforms. These operating systems will be customizable to let users run multiple operating system and application "personalities" on top of a single microkernel (92) .
Microkernel based systems can provide this flexibility because the core operating system functions are (93) from the large number of utilities, features and extensions that are layered on top of them. As a result, updating and maintaining operating system is easier, since developers don’t have to modify the (94) every time they must acid a new feature.

A:bases B:foundations C:systems D:foundation

For users, microkernel technology promises (90) , compact and sophisticated operating systems that are typically (91) across a range of hardware platforms. These operating systems will be customizable to let users run multiple operating system and application "personalities" on top of a single microkernel (92) .
Microkernel based systems can provide this flexibility because the core operating system functions are (93) from the large number of utilities, features and extensions that are layered on top of them. As a result, updating and maintaining operating system is easier, since developers don’t have to modify the (94) every time they must acid a new feature.

A:bases B:foundations C:systems D:foundation

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．
 

The information should be changed to bit（）before ．being transmitted

A:systems B:characters C:layers D:Streams