correct answer. a. Excretion b. Sensation c. Protection 1. The skin is the outermost protection of the body against injury and infection. 2. The skin contains receptors and nerve endings so that one can sense pain, heat, touch, and pressure. 3. The sweat glands release water through the pores when the temperature of a person rises. 4. The hair in the nose trap the dust particles in the air you inhale. 5. Excess salts and urea are taken out of the system in the form of perspiration.

19. ¿Cuál es el resultado de sumar las funciones \( f(x)=4 x^{4}-3 x^{2}+2 x+5 y \) \( g(x)=-x^{4}+2 x^{2}-3 x+6 \) ? \( \begin{array}{ll}\text { a) } 3 x^{4}-x^{2}-x+11 & \text { b) } 3 x^{4}-x^{2}-x+1 \\ \text { c) } 3 x^{4}-x^{2}+x+11 & \text { d) } 3 x^{4}-x^{2}+x+1\end{array} \)

(1 point) If the bacteria in a culture double in 1 hours, how many hours will it take before 6 times the original number is present? It will take hours. (Answer should be accurate to within at least three digits.)

5. \( 960 \mathrm{~mm}=\ldots \ldots \mathrm{cm} \)

Dans le plan complexe rapporté au repère orthonormal \( (0, \vec{u}, \vec{V}) \), soit \( A \) et \( B \) les points d'affixes respectives \( Z_{A}=\frac{1-i \sqrt{3}}{2} \) et \( Z_{B}=\frac{1+i \sqrt{3}}{2} \) a) Donner l'écriture exponentielle de \( Z_{A} \) et \( Z_{B} \) b) Placer les points \( A \) et \( B \) 2- soit \( C \) et \( D \) les points d'affixes respectives \( Z_{C}=1+\frac{\sqrt{3}}{2}+\frac{1}{2} i \) et \( Z_{D}=\frac{3}{2}-\frac{\sqrt{3}}{2} i \) a) Calculer \( / Z_{A}-Z_{C} /, / Z_{A}-Z_{D} / \) et \( / Z_{C}-Z_{D} / \) b) Donner l'interprétation géométrique de chaque module calculé. c) En déduire la nature du triangle \( A C D \)

El \( 40 \% \) de un curso está enfermo con una peste. Si en total solo 24 encuentran sanos, ¿cuántos alumnos tiene el curso?