Choose the sentence that has parallel structure. The teacher came into the room, quieting down the class and started the lesson.
The teacher came into the room, pausing before the class, and then beginning the lesson.
The teacher came into the room, he paused before the class, and beginning the lesson.
The teacher came into the room, paused before the class, and began the lesson.

i think it may be b, i'm not exactly too sure on this. but b seems to make more sense.

a solenoid is created by wrapping a l = 90 m long wire around a hollow tube of diameter d = 4.5 cm.   the wire diameter is d = 0.9 mm.   the solenoid wire is then connected to a power supply so that a current of i = 9 a flows through the wire.

randomized variablesl = 90 m

d = 4.5 cm

d = 0.9 mm

i = 9 a                                          

write an expression for the number of turns, n, in the solenoid. you do not need to take into account the diameter of the wire in this calculation.

calculate the number of turns, n, in the solenoid.

write an expression for the length of the solenoid (l2) in terms of the diameter of the hollow tube d.

calculate the length of the solenoid (l2)   in meters.

calculate the magnitude of the magnetic field at the center of the solenoid in teslas.

explanation:

answer: the prince warns the 2 families that if they get into another fight they will be put to death