What is the contra positive of the relation represented in the exhibit shown below?

A．R= {<1,2>,< 1,3>,<1,4>,<1,5>}

B．R= {< 1,1>,<2,2>,<3,3>,<4,4>,<5,5>}

C．R= {<2,1 >,<4,1>,<2,2>,<1,3>,<3,2>,<1,4>,<4,4>,<5,4>}

D．R= {<1,2>,<3,1>,<1,4>,<2,2>,<2,3>,<4,1>,<4,4>,<4,5>}

[单选题]What is the most important product-related factor the transport cost? （）A . LinkagesB . DistancesC . EquipmentD . Time

[单选题]What effect does excessive positive ions have on some people?A．They think they are mad.B．They feel very tired.C．They become violently sick.D．They are too tired to do anything.

[单选题] Which of the following statement related to PMO is not correct? (71)(71)A． The specific form, function, and structure of a PMO is dependent upon the needs of the organization that it supports.B． One of the key features of a PMO is managing shared re

[试题]In January 2008 Arti entered in a contractual agreement with Bee Ltd to write a study manual for an international accountancy body’s award. The manual was to cover the period from September 2008 till June 2009, and it was a term of the contract that t

Mobile telecommunications ______ is expected to double in Shanghai this year as

[单选题]Although the（ ）is a carrier in his relationship withthe actual shipper， he

[单选题]Although the（ ）is a carrier in his relationship withthe actual shipper， he

[名词解释] 被动体位（positive position）

But the philosophy of education must go beyond any idea of education that is for

[单选题]The book fair has received a positive __ from readers.A． resultB． responseC． settlementD． solution