1.compared to adults, a newborn breathes
a. a quarter as ofter
b. half as often
c. the same amount
d. four times as often
2.the cluster of air sacs at the end of each bronchiole is called
a. bronchi
b. traches
c. alveoli
d. bronchus
3.the flap of elastic cartilage that protect food from entering the larynx is called the
a. epiglottis
b. glottis
c. larynx
d. esophagus
4.when blood leaves the lungs it is
a. oxygenated
b. deoxygenated
c. exchanging gases
d. rich in carbon dioxide

Structures in cells that carry out specific functions.

Iron reacts with oxygen to produce iron oxide (rust). this reaction is represented in an equation as 4fe + xo2 → 2fe2o3. identify the value of x that will balance the equation.

Hydrilla (hydrilla verticillata) is an invasive aquatic plant and one of the most serious aquatic pests in florida. hydrilla has already been introduced to hundreds of bodies of water throughout florida, hydrilla is difficult to control because it grows rapidly and survives in many different water depths and conditions. hydrilla • describe how hydrilla affects native plant and animal species. include both a biotic and an abiotic limiting factor. • suggest one biotic and one abiotic recommendation that could slow the spread of hydrilla