Bronchi branch continually into smaller and smaller tubes and eventually end in sacs called
a. trachea
b. motor neurons
c. oblongata
d. alveoli

D. Alveoli
Bronchi branch into bronchioles, then bronchioles branch into large amount of alveoli

The answer is atmosphere. there are four spheres of the earth: 1. geosphere (from greek word 'geo' = ground), 2. hydrosphere (from greek word 'hydro' = water), 3. biosphere (from greek word 'bio' = life), and 4. atmosphere (from greek word 'atmo' = air). a magnetosphere is a region of space around astronomical objects controlled by the magnetic field of that object. through the process of elimination, since lightning is present in the air, it can be found in the atmosphere.

Your answer is going to be b.