阅读理解。

Oliver: Good afternoon, Mike.

Mike: Good afternoon, Oliver. What time is it now?

Oliver: It's five fifty. Why?

Mike: My mother is ill. My father isn't at home. I must go home and cook dinner.

Oliver: I'm sorry to hear that. Can you cook meals?

Mike: Sure. And I can wash clothes, too.

Oliver: You're helpful. I can't do that, but I can clean the room.

Mike: You are also helpful! I have to go. Goodbye!

Oliver: Bye.

根据对话内容，选择正确答案。

“总想看看你的笑脸……”，这与人的视觉形成有关：光穿过黑色的____      到达你的眼睛。在它周围的 ____   自动调整进入眼睛的光的量，当光很亮时，瞳孔收缩，当光很暗时，瞳孔____  。角膜具有保护瞳孔的作用。____就在瞳孔的后面，它的工作机理如同照相机的镜头。影像是在眼球后半部，即在____  上形成的。

I'm an English boy. My name's ______ .

如下图所示，位于湿润区的某河流，穿过平行的背斜山脉，进入平原。读图，完成下列各题。