More than fifty years after man first walked on the moon, space exploration continues to capture human imagination. Test yourself with these questions...

Various scales and charts have been developed to measure everything from the pungency of peppers to the intensity of earthquakes. Test your knowledge of some of them with these multiple choice questions...

Great architecture combines art and science to create structures of aesthetic appeal and functionality. Test your knowledge of this fascinating subject with these multiple choice questions...

Our planet is full of fascinating creatures with unique characteristics and often awe-inspiring abilities. Test your knowledge of the animal kingdom with these multiple choice questions.