某地一天的最高气温是12℃，最低气温是﹣2℃，则该地这天的温差是（   ）

①乐观是一种自信的表现，乐观的品质有助于成功

②乐观是一种自负的表现，不利于成功

③悲观是一种自卑的表现，不利于成功

④乐观者面对困难和失败不轻言放弃，对完成任务充满希望

从方框中选择合适的选项补全对话 (其中有两项是多余的)。

A: Excuse me, I'm a teacher from Chao Yang School. ____

B: Sure.

A: May I have your name please?

B: My name is Wang Duo.

A: ____

B: I'm in Grade 9.

A: ____

B: I like surfing the Internet and e-mailing people in different countries in my spare time.

A: ____

B: Yes, I think I can improve my English in this way.

A: Sounds great. What are the other advantages of your hobbies?

B: They can help me learn a lot about foreign cultures and customs.

A: Yes, they are really good for you.____

B: You're welcome.