如圖，AB∥CD，CB平分∠ABD．若∠C=40°，則∠D的度數(shù)為（　　）               

A．90°                         B．100°                       C．110°                       D．120°

方程組的解是（　　）                                                             

A．                     B．                     C．                     D．

下列計(jì)算正確的是（　�。�                                                                     

A．a(chǎn)²a³=a⁶                    B．（﹣2ab）²=4a²b²                                      

C．（a²）³=a⁵              D．3a³b²÷a²b²=3ab                                          

如圖，直線AB，CD相交于點(diǎn)O，因?yàn)椤?+∠3=180°，∠2+∠3=180°，所以∠1=∠2．其推理依據(jù)是（　�。�              

A．同角的余角相等     B．等角的余角相等                                        

C．同角的補(bǔ)角相等     D．等角的補(bǔ)角相等                                        

如圖，有以下四個(gè)條件：①∠B+∠BCD=180°，②∠1=∠2，③∠3=∠4，④∠B=5，其中能判定AB∥CD的條件的個(gè)數(shù)有（　　）                                                                                            

A．1                            B．2                            C．3                            D．4

已知x=2，y=﹣3是二元一次方程5x+my+2=0的解，則m的值為（　�。�                   

A．4                            B．﹣4                         C．                           D．﹣

計(jì)算2x（3x²+1），正確的結(jié)果是（　�。�                                              

A．5x³+2x                    B．6x³+1                      C．6x³+2x                    D．6x²+2x

有下列幾種說(shuō)法：                                                                              

①兩條直線相交所成的四個(gè)角中有一個(gè)是直角；                                             

②兩條直線相交所成的四個(gè)角相等；                                                       

③兩條直線相交所成的四個(gè)角中有一組相鄰補(bǔ)角相等；                                  

④兩條直線相交對(duì)頂角互補(bǔ)．                                                                  

其中，能兩條直線互相垂直的是（　　）                                                

A．①③                       B．①②③                    C．②③④                   D．①②③④

．如圖，下列說(shuō)法錯(cuò)誤的是（　�。�                                                       

A．若a∥b，b∥c，則a∥c                             B．若∠1=∠2，則a∥c           

C．若∠3=∠2，則b∥c                                   D．若∠3+∠5=180°，則a∥c         

若|3x+2y﹣4|+27（5x+6y）²=0，則x，y的值分別是（　�。�                         

A．                 B．                 C．                   D．