1. Yes, I think that teenagers use their phones a lot this days, maybe too much, but i’m not judging because I sometimes use my phone really much, even more then it’s healthy to.
2. The good things about having a mobile are that the phone it’s the easiest and comfortable way to use internet, have access to informations and even for school. They can be very helpful for everyone.
3. The bad things about using a mobile a lot is that can be unhealthy. It can cause vision problems, headaches, behavioural disorders, sleep disorders, backaches and neck aches and speaking of emotional problems, it can cause anxiety or even worse, depression.
4. Yes, I agree with the sentence, but I think that the “using the phone a lot” has for and against aspects, as I said earlier.
I hope it helped <3