1. Make up the sentences using the Passive Voice.
1) These documents (must sign) today.
2) This work (could finish) a week ago.
3) Dictionaries (can not use) during the exam.
4) The application (must fill in) with a pen.
5) The sick child (should examine) by the doctor.
6) The photocopier (may use) by anyone.
7) This story (should not tell) to little children.
8) Mobile phones (must not use) during a flight in airp
9) The dog (should take to the vet.
10) The parcel (could not deliver) yesterday.​

Many teenagers thought about how to finally become adults. Be independent of parents financially and manage your own life. Someone is ready to do it already 17, and the other can not be solved and in 20I believe that the norm for everyone is different, but when deciding when it is better to leave my parents, I would focus not on age, but on when a young man or a girl can independently pay for rented accommodation and offers himself. If this is possible, then it is considered that the person is independent of the parents. Usually they do not move for a long time because they can not rent an apartment or cook and wash themselves.But even if there are no domestic and financial problems, young people sometimes refuse to live separately. It can have many different reasons: for example, they can live independently, but do not believe in it. Or they have a special role in relations with parents and work in them. Children can consider: if I leave, parents will be bored or they will kill each other. Still life with the family is just convenient.
The fact that independent and financially independent young people do not start an independent life for a long time is a problem. This leads to greater infantilism, and the more a person is infantile, the less he wants to build a family and have children. Scientists conducted such an experiment: they provided the experimental mice to all, satisfied all their needs. As a result, mice simply refused to reproduce, they did not want to change their hedonic position.

People have the same thing: leaving parents means taking responsibility, and many people think that it's scary. They perceive it not as a right, but as a negative prospect: it is terrible to be responsible for one's life and build relationships. Some are sure that they must answer not only for themselves, but also for their partner, although this is not so: each person is responsible only for himself and only with the appearance of children already and for them too. And even this responsibility eventually passes to the children themselves.

Большой каньон  — один из глубочайших каньонов в мире.

Находится на плато Колорадо, штат Аризона, США, на территории национального парка «Гранд-Каньон», а также резерваций индейцев племен навахо, хавасупай и валапай.

Каньон прорезан рекой Колорадо в толще известняков, сланцев и песчаников. Длина каньона — 446 км.

Ширина (на уровне плато) колеблется от 6 до 29 км, на уровне дна — менее километра.

Максимальная глубина — 1857 м.

С 1979 года Большой каньон входит в список всемирного наследия ЮНЕСКО.

В пределах каньона наблюдается высотная зональность, хотя границы зон очень размыты.

С высотой изменяется температура, влажность и, соответственно, фауна, почвы и произрастающие на них растения.

В каньоне произрастает ель, жёлтая сосна, пихта.