All are correct except for 4.
The main verb is told.
1.Books do furnish a room
helping:do main:furnish
2.I am walking to school these days
helping:am main:walking
3.The water line must have burst.
helping:must have main:burst
4. I have told him not to call again
helping:have main:call
The main verb is told.
helping:were main:sent
6.Jolene will be decorating the gym for the costume contest
helping:will main:decorating
7.Clarence should have started his research earlier
helping:should have main:research
8.May I ask for volunteers?
helping:May main:ask
9.Raphael has been practicing karate since the age of ten
helping:has main:practicing
10.Your hard work will not be wasted
helping:will main;wasted
7. Wrong main verb
9., 10. Missing a helping verb
7 main started?
9 my helping is has and my helping for 10 is will
7. Yes
You have one correct helping verb, but 9 and 10 each has 2 helping verbs.
9. will be
Please note that not is an adverb and never a helping verb.