Relacionar Columnas Past Continuous: When ( Stopwatch4B, Workbook, exercise 3, page 144)Versión en línea Matching pairs por Andronica Ribera Moruco 1 She was doing yoga 2 He was riding his bike 3 They were studying for a math exam 4 She was walking her dog when the earthquake started. when she saw an accident. when someone knocked at the door. when his telephone rang.