Question 46: I/ never/ travelled/ by/air/ before. A. I have not never travelled by air before. B. I have traveled on air before. C. I have never travelled by air before. D. I has never travelled by air before. Question 47: It / important / keep/ environment / clean A. Its very important keeping the environment clean. B. Its very important to keep the environment clean. C. Its very important to keep the environment to clean. D. Its very important to keep an environment clean. Question 48: I /would / spend / vacation / a summer resort hotel. A. I would like to spend my vacation at a summer resort hotel. B. I would like to spending my vacation at a summer resort hotel. C. I would like spend my vacation at a summer resort hotel. D. I would like spending my vacation at a summer resort hotel. Question 49: I / happy / know / you / pass / entrance exam / become / student. A. I am happy know that you have passed your entrance exam become a student. B. I am happy to know that you have passed your entrance exam to become a student. C. I am happy to know that you had passed your entrance exam to become a student. D. I will be happy to know that you have passed your entrance exam to become a student. Question 50: How long / it / you / get / your school bus? A. How long does it take you to get to your school bus? B. How long does it spend you to get to your school bus? C. How long is it take you to get to your school bus? D. How long does it take you get to your school bus?