According to the passage, what makes mobile phones potentially harmful is ______.
A. their radiant light
B. their raiding power
C. their power of attraction
D. their invisible rays
* Đáp án
D
* Hướng dẫn giải
Đáp án D Giải thích: “What is it that makes mobile phones potentially harmful? The answer is radiation.” Radiation chính là những tia vô hình – invisible rays.