Many parents make their children do chores around the house. For some families, teaching children what to do and how to do chores is easy. But in other families, getting children to do some housework can be a very big problem.
   It is a good idea for parents to teach their children at an early age. All family members must work together to make the house clean, and each person must do his or her share(份) of the work. We can do this by starting plan of chores and responsibilities(责任) when children are young.
   Chores are good for children—even very young ones. Doing chores can teach children many important skills(技能) like working together. Jobs also teach children what is fair(公平). The skills and value(价值) from doing chores will be good to children all their lives. 

如图为脂蛋白结构图，下列关于脂蛋白的叙述正确的是（　　）

①图中X为磷脂，与蛋白质等共同构成亲水性微粒；

②图中Y含量相对少于胆固醇与胆固醇酯时，脂蛋白密度增高；

③HDL进入肝细胞后被溶酶体小囊泡消化，血液胆固醇含量降低；

④VLDL主要在小肠细胞产生，主要运输Y至肝脏储存．