Ecology is the study of how organisms interact with each other and their environment. It considers processes that occur at the population, community and ecosystem levels and has a particular focus on ...

Physics is the search for and application of rules that can help us understand and predict the world around us. Central to physics are ideas such as energy, mass, particles and waves. Physics attempts ...

We can ask about the subject or object of this sentence: Asking about the subject: Who met David Beckham? Sally met David Beckham. Asking about the object: Who did Sally meet? Sally met David Beckham.