阅读判断。
    Hello, my name is Tom. I like English very much. My favourite food is beef, rice and tomato. I'm very helpful. I can clean the room and wash the clothes. Today is Saturday. I often read books, do homework and watch TV.
    My home is near a river. There are some mountains behind my house. There is a tree in front of my house. You can see two bridges over the river.

体积为1L的某溶液中含有的离子如表所示：用Pt电极电解该溶液，当电路中有3mol电子通过时（忽略电解时溶液体积的变化及电解产物可能存在的溶解现象），下列说法正确的是（　　）

离子	Cu2+	Al3+	NO3﹣	Cl﹣
	1	1	a	1

已知向量| $\overrightarrow{a}$ |=2，| $\overrightarrow{b}$ |=1，（2 $\overrightarrow{a}$ ﹣3 $\overrightarrow{b}$ ）•（2 $\overrightarrow{a}+\overrightarrow{b}$ ）=9．

某学校七年级五班同学们组织开展了一次“我自信我成功我美丽”的主题体验活动。请你帮忙完成下列任务：

就业是民生之本。