sentence2_structure: A complex machine<>is described<>by: it is made of more than one simple machine$$$it<>is made<>of more than one simple machine
sentence1: Perhaps, in the future, we will describe a machine's behavior, not in terms of the simple sequences of events described in today's rules, but in terms of the more complex patterns of events contained in the tests.
sentence2: A complex machine is described by: it is made of more than one simple machine.
question: Which of the following statements best describes a complex machine?