According to the article, what happens to teenagers who get insufficient sleep?

Teenagers who experience the lack of sleep may experience drowsiness or fatigue. Teenagers may also experience physical inactivity due to fatigue. 

Teenagers are asked to not drive when they lack sleep, because lack of sleep is one of the major causes of major road accidents that leads to many fatalities. Which is why, parents are tasked to prohibit their children from driving, when they lack sleep.

The changes to agriculture in the united states since 1900 is that increased mechanization has increased food production, thereby increasing the need for labor. there has been an increased need for higher speeds of food production due the fact that the population in the united states continues to rise.