A

Mr. Smith：Good morning,class!

Students：Good morning,Mr.Smith!

Mr.Smith：Boys and girls,look at the picture,please.What's this in English? Is this a pen,Bob?

Bob：Sorry,Idon't know.

Mr.Smith：Frank,what's this?

Frank: It's a key.

Jenny：No.It's a ruler.

Mr.Smith：Can you spell it,Jenny?

Jenny：R-U-L-E-R,ruler.

Mr.Smith: Very good! Now let's look at another(另一个)picture.

根据对话内容,选择最佳答案。