A.not everyone needs to use a cellphone |
B.cellphones are the most important thing in our life |
C.cellphones play an important role in our life |
D.cellphones have different functions for different people |
A.Whether radio signals cause health problems or not. |
B.Whether using a cellphone for too long can lead to brain cancer. |
C.Whether cellphones have more advantages than disadvantages. |
D.Whether people worry about talking on the cellphone for too long. |
A.people use cellphones for too long every day |
B.using cellphones has an effect on brain cells |
C.cellphones that are powered off can also affect the brain |
D.increased activity in brain cells has many causes |
A.Cell phone safety is not an important issue. |
B.It goes without saying that cell phones harm people’s health. |
C.Few studies have been done on whether cell phones are safe to use. |
D.There is still a long way to go to find out whether cell phones are safe to use. |