【单选题】The potential support ratio, or PSR (the number of persons aged 15-64 years per one older person aged 65 years or older), indicates the dependency burden on potential workers. The impact of demographi...
【简答题】12-65. Which of the following sentences is INCORRECT? (1.0分)A. A. New machinery were introduced in the factory. B. B. Poultry are very expensive in the city. C. C. The police are investigating the mur...