阅读下面短文，从每题所给的A、B、C、D四个选项中选出最佳选项。

Hi! I'm Alan. This is my dream house（梦幻屋）. It has a small but nice room. Some pictures are on the wall. There is（有） a bookcase in my room. There is a desk and a chair in it. My schoolbag is on the desk. There are two baseballs near it. Oh! Where is my pencil case? It is under the chair. There are some pencils and a ruler in the pencil case. My bags and a basketball are under the bed. I like my dream house very much.

下图为某年中国北方某市城郊温差的日变化示意图。据图可知（    ）

10月16日济南迎来2015年最大雾霾，百米距离难看清，机场半小时停止起降，下图为我国四个雾霾多发地区，图中四地深秋初冬时节多雾，其原因说法正确的是（     ）