C
Kiến thức: từ vựng
Giải thích:
advise (v): khuyên bảo involve (v): liên quan
show (v): chỉ ra recommend (v): gợi ý
Which of the following is closest in meaning to crux in paragraph 4?
The changes possibly caused by the cell phones are mainly concerned with ____________.
Compared to preindustrial times, the number of hours in the workweek in the nineteenth century______.
The man mentioned in the passage, who used his cell phone too often, ____________.
According to the passage, what makes mobile phones potentially harmful is ____________.