已知x+y=3，xy=1，求代数式（5x+2）﹣（3xy﹣5y）的值．

阅读短文，从A、B、C、D四个选项中，选出可以填入空白处的正确答案。
    Look at this picture. It is 1 nice classroom. In the picture, you can see a teacher's 2 on his desk. It's a Chinese book. Eight desks and eight chairs in the room. You can see a girl and 3 boys.
    The girl's 4 is Julia. She is eleven. The boy 5 a black hat is Tom. The other boy is Tony. They 6 the same coats and they are the same age. I 7 they are twins. Tom is a 8 boy. A book is in his hand. You 9 see the teacher . 10 is the teacher? He is taking the photo

已知点O（0，0），B（1，2）．

人体排尿的生理意义是（   ）
①调节体内水的含量             ②调节体内无机盐的含量 
③排出组织细胞产生的废物       ④维持组织细胞的正常生理功能