Answer:
See below for the first several answers.
Explanation:
C'est mon crayon. (because my is mon/ma/mes and agrees with the object)
C'est ta gomme. (because your is ton/ta/tes and agrees with object)
Ce sont ses feutres. (because his is son/sa/ses and agrees with object)
C'est son sac à dos. (because her is son/sa/ses and agrees with object.
C'est ma trousse. (because my is mon/ma/mes and agrees with object.)
Ce son mes cahiers. (because my is mon/ma/mes and agrees with object)
