1. It takes him two hours to do his homework(make a question for underline part)(phần gạch chân là two hours) 2.ethnic groups/still/traditional/Some/life/in/ways/mountains areas/their/keep/of.(rearrange the words to make a complete sentence) 3.The cultural heritage of the ethnic peoples in Vietnam is very rich.(make a question for underline part)(phần gạch chân là very rich) 4.The Muong/Thanh Hoa/well-known/the richness/their folk literature.(use the words to make a sentence)