如果为下列三幅图片反映的历史事件拟定一个主题，最恰当的是

2014年5月，一个国际科研团队宣布其用钙原子轰击放射性元素锫，成功合成117号元素（部分信息如图所示）．下列说法错误的是（   ）

①微博议政开辟了公民行使民主权利的新途径

②微博议政说明了公民参政议政意识的增强

③只有网络才能搜集到真实的社情民意

④微博议政有利于公民直接参与国家事务的决策

如果a²=25,$\left|b\right|=3$,且a＜b那么 a+b 的值为  (  ）

任务型阅读

　　There are some students in front of the lost and found box. The duty monitor Alan is asking some questions.

Alan: Jim, is this your English book?

Jim: No, it isn't.

Alan: Linda, is this your English book?

Linda: Yes, it is. Thanks.

Alan: Gina, what colour is your pencil?

Gina: It's green.

Alan: Is this your pencil?

Gina: Yes, it is. Thank you.

Alan: What is your name?

Jenny: My name is Jenny.

Alan: Is your ruler green or yellow?

Jenny: It's green. There’s my name “Jenny” on it.

Alan: Oh, here you are.

Alan: Here’s a nice bag; whose bag is this?

Paul: Let me see. . .  Oh, it's mine.

Alan: Look at the cute doll. Is this yours, Mary?

Mary: No, it isn't. I think it’s Betty's. Is there a watch in it?

Alan: Sorry, I haven’t seen it so far.

根据对话内容, 完成以下任务。