“吸烟有害健康，拒吸二手烟”．香烟燃烧产生的烟雾中含有尼古丁（化学式为C₁₀H₁₄N₂）、一氧化碳等．下列说法中错误的是（　　）

已知$\frac{\mathrm{\pi }}{2}<\alpha <\mathrm{\pi }$，sinα=$\frac{4}{5}$，

（Ⅰ）求tanα的值；

（Ⅱ）求cos2α+sin（α+$\frac{\mathrm{\pi }}{2}$）的值．

节日知识大比拼。

读一读，连一连。

清明节____      吃粽子

中秋节____      扫墓

春节____        吃月饼

端午节____      拜年

   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.