What is the simlarity of goblet cells and cilia?
a. both moisten the air.
b. both filter the air.
c. both secrete mucus.
d. both diffuse oxygen.

What is the main reason that attitudes are more often revealed in spoken rather than written language? a. in writing, we try to put the "best face" on what we write. b. we speak far more often than we write. c. in writing, we can more easily conceal our attitudes. d. in spoken language, we are often careless in our use of words.