An example of a grad-school level question?
Some machines can remove the salt that is in seawater. How does removing salt from seawater most help people?

An example of a grad-school level question?
Single-celled organisms can reproduce and create cells exactly like themselves without combining genes from two different parent cells. When they do this, they use a type of

An example of a grad-school level question?
A student leaves a rock in the Sun on a bright afternoon. An hour after sunset, the weather is cool, but the rock still feels warm. The student has demonstrated a property of the rock resulting directly from which of the rock's other properties?

An example of a grad-school level question?

Which of the following is a property of CO2 gas?