This letter, this pencil., that man, that woman, this desk, this office, this house, this cable, this city, that class надо во множественном числе.

This letter-these lettersthis pencil.,-these pencils that man,-those men that woman,-those women this desk-these desks, this office,-these offices this house,-these houses this cable,-these cables this city,-these cities that class-those classes

this letters, this pencils., this men, this women, this desks, , this houses,it offices, this tables, this cities, this classes