Generate the answer for a given question. The question requires common knowledge of English. Make sure that the answer is in detail, long, consistent with the context, and requires general knowledge of English. To be less repetitive, please vary your language for each question. Give a proper explanation to answer, and if necessary, provide the definition of various terms. And conclude your answer if it's long. If you have used other resources (e.g., Merriam Webster's.) to answer the question, include citations in your answer. You don't need to paraphrase the context of your resources, but make sure that your answer is consistent and complete.

Example Input: Is there a noun or adjective for the following or similar: a pleading before a judge for clemency a prayer before God begging for mercy Is there a better word than 'begging', 'pleading', 'petitioning', etc.?.
Example Output: Judge or God, clemency or mercy.. Supplication, a noun, can logically be applied to any situation in which you plead to someone in power for help or a favor. Supplication: comes from the Latin verb supplicare, which means 'to plead humbly.' (etymonline.com) Supplication (also known as petitioning) is a form of prayer, wherein one party humbly or earnestly asks another party to provide something, either for the party who is doing the supplicating (e.g., 'Please spare my life.') or on behalf of someone else (e.g., 'Please spare my child's life.'). (wiki)

Example Input: Is there a single word to describe birds that can fly? Am I struggling to think of a word because the default notion of a bird is that it can fly? So we generally only need to differentiate the ones that can't fly. I've seen the term 'winged' in a few google searches, but to my mind an ostrich is winged, but it is also flightless. I guess I'm looking for the word you'd put into this blank: Penguins are flightless because they cannot fly. Ostriches are flightless because they cannot fly. Pigeons are ____ because they can fly.
Example Output: I think you can just use flying to describe them; flying birds sounds perfectly normal and isn't a tautology, nor does it only apply to birds in the air, cf. the title of the Wikipedia article 'Flying and gliding animals'. It's obviously an awkward choice for your example sentence, where another option, volant, could be used instead: 2: flying or capable of flying (source: Merriam-Webster)

Example Input: I've been asked to give lectures on electromagnetism in English, but I encounter many problems trying to express mathematical formulas since they are written and I do not know how to read them. Are there any references which elaborate the formulas and express what should we call any mathematical sign?.
Example Output:
The following references are useful: Pronunciation Guides for Mathematical Notation, Expressions, and Greek Letters (Reference list) Reading Mathematical Expressions (PDF) How can we speak math? (PDF)