Please help me solve this questions one after the other, please​

In what for do plants utilize nitrogen? why do they need nitrogen?

Astudent reads the following text in a science book: scientific evidence tells us that the cause of earths four seasons is the tilt of earth as it revolves around the sound the student is instructed to illustrate this information in a science book. how will the student illustrate winter in the northern hemisphere? a.earths northern hemisphere will tilt away from the sun. b. earths northern hemisphere will tilt toward the sun. c.earths orbit will be farther away than from the sun d. earths southern hemisphere will tilt away from the sun.

Achild is suffering from fever but the doctor cannot immediately pinpoint the alignment on the basis of this one symptom explain why also mention other two such general symptoms