Awonderful time was being had by everyone at the party. which revision changes the sentence’s verb from passive voice to active voice? at the party, a wonderful time was had by all. a wonderful time had been had by everyone at the party. everyone was having a wonderful time at the party.

not concrete, existing in thought or as an idea but not having a physical or concrete existence

  this riddles' answer is library.

  the "leaves" are a reference to the books' pages that the library contains; the branches are a network of libraries that connect multiple libraries' collections, resources, and items in a system of a common database, integrating them; the branches' organization are a useful management tool for coordinating the multiple collections many libraries have.