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