Русско-английский научно-технический словарь
требоваться
см. тж. для ... требуется; когда это необходимо; необходимо
• Where self-priming qualities are called for (or required, or needed, or necessary, or essential), ...
• It takes a very powerful magnetic field to control the path of ...
• Additional information must be called on to describe the eigenfunctions in more detail.
• It takes a second to form a wave.