An example of a grad-school level question?
Which SI unit would be most appropriate for recording the length of a typical classroom?

An example of a grad-school level question?
The smallest unit of a plant that can perform all of the processes of life is the

An example of a grad-school level question?
Which of these provide the best evidence that life could develop on Mars?

An example of a grad-school level question?
Which statement best explains Earth's day and night cycle?