Insomecountriesinwhichthereisverylittlerainatanytime,...
問題詳情： Insomecountriesinwhichthereisverylittlerainatanytime,thefarmershavetoirrigatetheirfields.Irrigationiseasyenoughifthereisagreatrivernearthecrops,andifthereisplentyofwaterinit.Canalscarrythe...