-Modern technology allows us to communicate people within seconds.A lot of teenagers are hooked their gadgets.Jack is always glued the TV and never does anything.He doesn't participate online games.She is in touch her friends almost all the time.​

Вопрос с "хвостом" "Tag question"
We didn' t meet on Sunday, did we?
The puipls are seldom late, aren't they?
We can sing English songs, can't we?
They never play on the floor, don't they?
There is no boockase near the wall, isn't there?
There were plants in that classroom last year, weren't there?
Pupils don' t often laugh at Maths, do they?
We shall study Art next year, shan't we?
в "хвосте"(слова после ",") используем 1)глагол или связку:  В положительной форме , если в основной части он в отрицательной; в отрицательной если в основной части глагол в положительной, то есть наоборот. 2)ставим местоимение или часть структуры (местоимение можем делать из существительного)
получаем
основа : we didn't, хвост: did we? и т.д.
Понятно объяснил?
P.S. Торопился, поэтому за ошибками не следил.

1. It is one of the most famous squares in the world. 
We can see Lenin's mausoleum,  St. Basil Cathedral,  the State Historical Museum  and  the Kremlin there .2. It is former tsar's residence, now it's a city and a Park-Museum. We can see there Grand Peterhof Palace, Grand Cascade and a lot of other different fountains.3. The Hermitage, the Russian Museum 4. Alexander's Garden 5. The Bolshoy Theatre 6. The Mariinsky Theatre 7. The Armoury Chamber showcases ancient state regalia, ceremonial tsar’s vestments and coronation dress, vestments of the Russian Orthodox Church’es hierarchs, the largest collection of gold and silverware by Russian craftsmen, West European artistic silver, ceremonial weapons and arms, carriages, horse ceremonial harness.