C.tt is the correct answer
Answer:
Respiratory epithelial cells line the respiratory tract from trachea to bronchi into bronchioles and alveolar sacs. ... The goblet cells produce and secrete mucous to trap pathogens and debris within the airway tract. Basal cells are progenitor cells that differentiate into cells types found within the epithelium.
The answer is A. C and G go together and A and T go together.
Primary succession is ecological succession that begins in essentially lifeless areas, such as regions in which there is no soil or where the soil is incapable of sustaining life because of recent lava flows, newly formed sand dunes, or rocks left from a retreating glacier.
