Read these sentences and choose the correct variant.

1.
We must stand up when the teacher arrives in the classroom
We must to stand up when the teacher arrives in the classroom

2.
You must cleans up your room
You must clean up your room

3.
I have a special talent, I can reading very quickly
I have a special talent, I can read very quickly

February 14, 1876, alexander  graham  bell (1847-1922), professor of physiology  ofspeech  at boston university, has patented  his invention  in the u.s.  - the phone.if we talk about  the specific purpose  of the inventor, it  appeared,  as they say,  by accident.  but the idea of  creating  the usual  phone  for all of us  were not born  in a vacuum.