Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions. Travelling by air is a little bit expensive. My father suggested we by tĐoạn văn9/40Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions. Travelling by air is a little bit expensive. My father suggested we by train.goingwill gogoto goGiải thíchC. go