Use -ist, -or, -er to form nouns e. g. write – writer 6 play - 7 cycle - 8 direct - 9 football - 10 art - 11 paint -

1. сильно ли ученики от того, что носят в школу портфели с тяжелыми учебниками?   yes, they  do -  да 

2. вызывает ли это серьеные проблемы со здаровьем? yes, it does - да, вызывает

3. как действует зкран компьютера на глаза человека? it makes human  eyes see worse.  он ухудшает зрение человека.

4. излучает ли экран компьютера радиацию? yes, it does -  да

5. обязаны ли большенство пользователей носить очки?   yes, they do -  да, обязаны

6.  не лучше ли во многом для глаз человека пользоваться напечатанным изданием?   yes,  of course  -  конечно, да 

in ancient поверьях water is blood of live mother of the crude earth, and support upon which the earth, and a watershed between the world live is based and kingdom beyond the grave. call her in the people precisely "mother", "tsarina". at a dawn of human history people distinctly understood great value of water elements. it is confirmed also with mythology of all countries both all people, and the latest philosophical systems: as without fire isn't present cultures so without water isn't present and there can not be a life. in compliance with the such understanding of a world role of water the pagan people invariably idolized these elements as a life perennial spring, as eternally live spring, at which help other great elements - the earth were impregnated.