根据对话内容回答问题
A: Hello! Is that Mike?
B: No. This is Tom.
A: Hi, Tom. This is John. How are you?
B: Fine, thanks.
A: Is Mike in?
B: Sorry, he isn't. He's at school.
A: OK. Thank you. Bye—bye!
B: Bye!
下列物体的主视图、俯视图和左视图不全是圆的是（ ）
