1. They don't have tolmustn't chat to strangers on the internet. 2. Anna to concentrate more in lessons.a) mustn'tb) shouldn't stay upc) must finishd) must gete) should try3. 1 to stay in touch with them.a) help around the houseb) do something creativec) chat with friends onlined) do sportse) get enough sleep4. People forgot how important it is to do this. And it's much bea) exercise regularlyb) drink waterc) cook fresh foodd) take a breake) have a hobby5. - I'm not sure how to use this computer.a) -OK, perhaps you are right.b) -Yeah, sure. What's up?C)Yes.d) -Let me show you.e) -That's really kind.​