Do you like Home with Kids(《家有儿女》)?It is very popular(受欢迎的)now. Many children like it. There are five people in the family. There is a sister and two brothers in their family.

   Their father is a film director(导演). He doesn’t often do housework. He is always happy. Their mother doesn’t go to work. She stays at home and does housework. And she loves her children very much, but she gets angry easily. Xiaoxue is their daughter. She is a good student. Big brother, Liu Xing, can always make others happy. He likes ball games. Little brother, Xiaoyu, is helpful. He likes playing computer games. This is a happy family.

已知函数f(x）=-2(x+a)lnx+x²-2ax-2a²+a，其中a>0.

如图中长方形高度表示甲、乙、丙、丁四种组织处，血红蛋白与氧气的结合情况．试推测甲、乙、丙、丁四种组织中呼吸作用最旺盛的是（  ）

吃玉米棒子和葵花籽时，常发现玉米果穗再现“秃顶”、葵花籽出现空瘪现象。其主要原因都是（  ）

下列各句中，没有语病的一项是（   ）