A vehicle's oil pressure warning light is on. Technician A says that the pressure sending unit should be replaced and the vehicle re-checked. Technician B says that a mechanical oil pressure gauge should be used to check the oil pressure before replacing the sending unit. Which technician is correct?

Technician B is correct

Explanation:

Unless the car owner just put oil in the car, the sudden distrust of the pressure sending unit is alarming.

Even if the car owner just replaced oil, so many other things can cause a running out of oil.

So, the better option is to check the oil pressure with a gauge outside of the car system before deciding to replace the pressure sending unit.

answer;

d. are made mostly of liquid

explanation;

-the general   composition and structure planets includes; they have a thick gas and liquid layer covering a small,solid core. mostly the gases are hydrogen and helium atmosphere and layers of liquid hydrogen. for instance neptune and uranus are examples of the outer planets, they have a core covered by ice and ammonia.

-neptune's atmosphere is hydrogen and helium with a bit of methane so there is no oxygen to breath and the interior is made up of frozen water and ammonia with a rock and iron core. thus, there is no liquid water or solid surface to survive.