Jack is not old, but he doesn't have much hair. His wife Alice has thick(厚的)and black hair.

    They have a daughter(女儿). Her name is Kitty. And Kitty is five years old. 0ne day, Jack is reading a book in his room. Kitty looks at her father for a long time and says to her mother,“Why does father have so little hair?”“He has little hair because(因为)he thinks a lot. He is a very clever(聪明的)man. ”Alice says with a smile(微笑).

已知命题p：若实数x，y满足x²＋y²＝0，则x，y全为0；命题q：若a>b，则$\frac{1}{a}$<$\frac{1}{b}$，给出下列四个命题：①p∧q；②p∨q；③ $\neg$p；④ $\neg$q.

其中真命题是（  ）．

“天宫一号”围绕地球做匀速圆周运动过程中保持不变的物理量是（   ）

读图，完成下列各题。