An example of a grad-school level question?
The Sun appears larger than other stars because of its

An example of a grad-school level question?
During a lab investigation a scientist heats a solid substance. The scientist observes that the solid has two different melting points. The scientist is able to separate the two resulting liquids. Which statement best classifies the original solid substance?

An example of a grad-school level question?
Which of these makes it possible for hurricanes to form?

An example of a grad-school level question?
Which of the following best explains why the Sun appears to move across the sky every day?