平面内的两条直线相交和平行两种位置关系，如图①，若AB∥CD，点P在AB、CD外部，则有∠B=∠BOD，又因为∠BOD是△POD的外角，所以∠BOD=∠BPD+∠D，得∠BPD=∠B﹣∠D．

实验室用NaOH固体和蒸馏水准确配制一定物质的量浓度的NaOH溶液．以下仪器中，不需要用到的是（　　）

选择相对应的答句

____What's your father's job?                                     A. Eleven.

____Who are they?                                                        B. They are my parents.

____How many people are there in your family?          C. He's a doctor.

____Who's this woman?                                                D. Yes, he is.

____Is this your uncle?                                                   E. She's my aunt.