Which sentence uses active voice?
a. The bill was vetoed by the governor.
b. the mechanic replaced the air filter.
c. the celebrity was hounded by photographers.
d. the decision was made by the whole committee.

As the boys sleep, military airplanes battle fiercely above the island. none of the boys sees the explosions and flashes in the clouds because the twins sam and eric, who were supposed to watch the signal fire, have fallen asleep. during the battle, a parachutist drifts down from the sky onto the island, dead.

This is a complete adjective clause.