6. a .who giải thích : he was respeter by the people with who he worker
7. c .telephone i sent a telephone to my mother saying i had arrived arrived safely
8.a .can't she lisa's been able to play the flute since she was six, can't she
9. a .fly yuri gagarin is the first man to fly into space
10 a .traintional we should develop such traintional sources of energy such as solar enery and water enery
