【单选题】In an economy, 42 million people are in the labor force, 38 million are employed, and 47 million are of working age. How many people are not in the labor force?
【简答题】A.The mental disorder is very serious. B.Many people are not as serious as they've been told. C.The symptoms are easy to be defined. D.More and more people are caught by the psychological disorder.