4.Politeness is a(n) ____ phenomenon among all the social groups, but it is marked by different cultures.
—I'm going to travel along the Mekong River next week. —______________.
After working for two hours, I foundimpossible to complete the paper in time.
Although ________ to stop, he kept on working
Was_______ John’s quick action and knowledge of first aid ________ saved her life?
Only after you have reached eighteen _______ the army.