điền dạng đúng của từ 8. If you are going to Son Doong Cave, you really need to book a __________________ tour because you will easily get lost there. (GUIDE) 9. In some Asian countries such as India, Pakistan, the Philippines and Singapore, English is used as the __________________ language. (OFFICE) 10. The variety of dialects and accents in English is one of the biggest challenges to __________________ English speakers. (NATIVE) 11. Oranges, sunflower seeds and salmon are believed to support blood __________________in our body. (CIRCULATE) 12. Although canned food is convenient, it is not good for your health because it contains __________________. (PRESERVE) 13. Most of visitors can’t help being amazed by the __________________ of Edinburgh Castle. (MAGNIFY) 14. The heavy rains cause river levels to rise and make the cave largely __________________. (ACCESS) 15. My English teacher told me that some sentences in my essays were not __________________ correct. (GRAMMAR) 16. English has grown from a language of few speakers to become the dominant language of international __________________ . (COMMUNICATE) 17. Until the 1600s, English was, for the most part,__________________ only in England and had not extended even as far as Wales, Scotland, or Ireland. (SPEAK) 18. English began to spread around the globes as a result of __________________ , trade (including slave trade), colonization, and missionary work. (EXPLORE) 19. Thus, small enclaves of English speakers became established and grew in __________________ parts of the world. (VARY) 20. Two-thirds of the world’s science writing is in English, and English is the main language of technology,__________________, media, international airports, and air traffic controllers. (ADVERTISE)