An example of a grad-school level question?
A student uses a high-efficiency gasoline lawnmower to cut grass. The term "high efficiency" is used to indicate that the lawnmower

An example of a grad-school level question?
When Isaac Newton theorized that gravity caused objects to fall to the ground, he had also discovered the force that causes

An example of a grad-school level question?
Which of these human activities in a forest has a positive effect on the ecosystem?

An example of a grad-school level question?
In what way do transit systems, such as buses, benefit society?