1) They sit in his livingroom at the moment.
A B C D
=> are sitting
2) He is the cleverer student in my class
A B C D
=> cleverest
3) The teacher is standing at the middle of the room now
A B C D
=> in
4) She would like send this letter to the USA
A B C D
=> to send
1A sit -> are sitting
2B cleverer -> cleverest
3C at -> in
4B send -> to send
1. A ->is sitting
2. B ->cleverest
3. C->in
4. B->to send