Ответ:

People spend hours talking on their mobile phones. There is an opinion that it may be ________HARMFUL__________ to their health, but it is difficult to know for sure. Some research shows that mobile phones may cause brain problems. On the other hand, some doctors say mobiles are not ________DANGEROUS__________ at all. No matter what doctors say, it’s just _________IMPOSSIBLE_________ to live without a mobile phone today. It has become a very ________USEFUL__________ device and people can’t do without it. It makes our life _________COMFORTABLE_________ and saves time. People can get in touch with each other quickly. Mobile phones make _________COMMUNICATION_________ easier.