Identify the reason the following sentences are not formal sentence definitions. Rewrite each into a correct formal sentence definition.

a. A dribble is a basketball move.
b. A heel is part of the foot.
c. Sleet is when snow in the upper atmosphere melts and refreezes when it hits the ground.
d. A gazebo is open on all sides.
e. An ambulance siren signals that an ambulance is coming.
f. A backyard deck is a deck in the backyard.
g. An astrolabe in the sixteenth century was used to calculate the position of the stars.
h. Doubles tennis requires two players on each side.
I. A harp is a musical instrument.
j. T
o surf means to surf the waves on a surfboard.