To conserve fuel and extend the life of your vehicle, you should
a. drive so you keep the engine cold.
b. plan ahead and combine short trips into one slightly longer one.
c. always take only short trips.
d. make accurate use of road maps

Suppose you are a freshmen in college and you have not declared a major. one reason you enrolled at your respective college was the school's vibrant social life. at the same time, you want to balance your academic life because you know that your grades will matter for graduate school or job applications.you decide to forgo partying for two hours to study for an upcoming economics exam. in your first semester's principles of economics class, you learn that the enjoyment you would have received from partying is an example of a(n)