Which sentence is written in standard English? I should have gone with my brother to that thing.

They ought to take the books back to the library.

We have twenty days max to finish the project.

He is the sort of person who is up for anything.

Im pretty sure its B, but if not then d

Explanation:

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 is b,

"the tracer looks harmless in flight, but the pilot’s bitten lips and white knuckles suggest how dangerous it can be."

it was correct.