情景对话。

A: Good moring, Mr Green!

B: Good moring. What's your 1.               , please?

A: My name is Li Ming. 2.                 are you, Mr Green?

B: Fine, thanks. 3.                 you?

A: I'm fine, 4.                 Thank you.

B: What 5.                are you in?

A: I'm in Grade Two.

B: Are you in Class 3?

A: 6.                . I'm in Class 1.

B: How 7.                  are you?

A: I'm eleven.

B: 8.                 do you go to school?

A: By bike.

B: By the way, is this 9.                 key to the bike?

A: Yes, it's mine. Thank you.

B: You're 10.                .

若以下选项中的变量已正确定义，则正确的赋值语句是( )。

A．xb26.8%3;

B．1+2=x2

C．x3=0x12;

D．x4=1+2=3;