6. So many people nowadays are ...computer and mobile phones. They use them a lot. A. addicted to B. bored with C. worried about D. afraid of    

C. worried about - There are also individuals who are worried about the impact of excessive use of computer and mobile phones on their health and relationships.

B. bored with - Some people may feel bored with computer and mobile phones if they use them too much and want to disconnect.

A. addicted to - Many people nowadays are addicted to computer and mobile phones, using them a lot in their daily lives.