38. The students / our school / often / collect / waste paper / their mini project /. A. The students in our school often collects waste paper for their mini project. B. The students in our school often collect waste paper for their mini project. C. The students on our school often collect waste paper for their mini project. D. The students in our school don’t often collect waste paper for their mini project. 39. My aunt / have / small garden / and / she / grow / flowers / vegetables /. A. My aunt have a small garden and she grows flowers and vegetables. B. My aunt has a small garden and she grow flowers and vegetables. C. My aunt has a small garden and she growes flowers and vegetables. D. My aunt has a small garden and she grows flowers and vegetables. 40. Don’t / throw / plastic bags / because / you / reuse /. A. Don’t throw the plastic bags because you can’t reuse them. B. Don’t throw the plastic bags because you can reuse them. C. Don’t throw the plastic bags but you can reuse them. D. Don’t throw plastic bags because you can reuse.