What is meant by an essential nutrient? Why might nutrients be referred to as essential? Please help, and quick!

Which of the following is an important function of child-directed speech? (a) it captures the infant’s attention and maintains communication. (b) it reduces the occurrence of infantile amnesia for the earliest memories of infancy. (c) it reduces the need for reciprocal interaction between caregivers and children. (d) it assists in prolonging rem sleep in infants.

The five components of health-related fitness include cardiorespiratory fitness, muscular strength, resting heart rate, muscular endurance, and body composition cardiovascular fitness, muscle tone, muscular endurance, flexibility, and body composition calisthenics, muscular strength, muscular endurance, flexibility, and body composition cardiorespiratory fitness, muscular strength, muscular endurance, flexibility, and body composition

You should never drive a car if you are a.taking cold medication b. suffering from the flu c. drinking alcohol d. all the above