He made up his mind to devote his life ______ the river ______ polluted.
Will you ____my composition to find out whether I’ve made any spelling mistakes?
Not far from the club there was a garden, ____ owner seated in it playing bridge with his children every afternoon.
The person we referred to____ us a report tomorrow.
The person we spoke to ____ no answer at first.
The person we talked about ____ our school last week.