Why is the outside lining of the lungs lubricated?

You should never drive a car if you are a. taking cold medication b. suffering from the flu c. drinking alcohol d. all the above

*edit* i took the test and i picked a and it was incorrect for its c! rank the following suggestions for preventing std, in order of increasing effectiveness. 1) using latex condoms properly 2) using spermicidal foam or jelly with a monogamous partner 3) abstaining from sexual intercourse and genital contact a. 1, 2, 3c. 2, 1, 3

Aspeed limit sign that says "night" indicates the legal speed between sunset and sunrise. a. minimum b. maximum c. only d. average