根据对话内容，用恰当的单词、短语或句子补全对话。

A: Look, Mona ！?

B: Oh, it's a person computer. It is widely used in today's world.

A: You are right. Do you know ?

B: Yes, it was invented in 1971.

A: ?

B: It is used for helping us work , study , send e﹣mails and so on.

A: ?

B: It is said that it was invented by some American scientists.

A: By the way, what are you going to be when you grow up ?

B: and invent many useful inventions for our motherland.

A: OK. Let's work hard to make our dreams come true.