Pouvez-vous m’aider svp c’est pour mardi

L'énoncé te dit d'utiliser le present perfect

For --> durée

Since --> date précise

a. has polluted (present perfect), for

b. has been (c'est la troisième personne), since

c. since

3. has become (pareil, 3è personne), since

4. have not seen (present perfect), for