Well, some things people should remember - how to calculate the hypotenuse of a right-angled triangle, or who the parties were in WW2, or what makes a metaphor different from a simile.

But you can also give problems, like 'here are the dimensions of some real-world problem, and here's a formula used to solve such problems, apply one to the other'; or 'here's the text of a poem by so-and-so, explain what you think the poet means and support your arguments with reference to the text.'

I know essay answers take longer to evaluate and are harder to score, but I get the impression that way too much of k-12 educational testing involves multiple-choice questionnaires.