题干
— Why not read the book on the grass, Steven?
— Reading books in the Sun is harmful to my eyes.
— Reading books in the Sun is harmful to my eyes.
A：is helpful
B：is good for
C：is bad for
答案(点此获取答案解析）
C
，L1跟竖直方向成60°角。下列说法中正确的有 
