肺癌的发生与下列哪项关系最密切（）
A.环境空气污染
B.吸烟
C.职业致癌因素
D.肺部慢性病变
E.遗传因素
参考答案：B
请在图中画出对应的反射光线和大致的折射光线。
Can you lend me the book ________ the other day?
A．about which you talked
B．which you talked
C．about that you talked
D．that you talked
