Tìm lỗi sai và giải thích giúp mình với nha! Mình muốn hiểu tại sao lại sai ở đó! 1. 'There were'(A) so 'a lot of'(B) people trying to leave 'the burning'(C) building that the police had a 'great deal'(D) of trouble controlling them. 2. I 'still'(A) have to 'finish'(B) my project, 'what'(C) keeps me 'very busy'(D). 3. 'The more'(A) healthy he 'is'(B), the 'most easy'(C) his life 'becomes'(D). 4. 'Despite'(A) its 'smaller size'(B), 'the'(C) Indian Ocean is 'as deep'(D) the Atlantic Ocean. 5. The 'number'(A) of 'visitors'(B) to the 'exhibition'(C) dropped 'considerable'(D) in the second week. 6. When too 'many'(A) firms enter 'competitive'(B) markets, 'their share'(C) of profits 'will fell'(D). 7. The term "middle class" 'describes'(A) people 'between'(B) the upper and 'the low'(C) social 'classes'(D). 8. Nowadays 'there are'(A) 'more'(B) and more places 'when'(C) we 'cannot'(D) use our phone. 9. 'Almost'(A) American Indian cultures 'have been'(B) 'agricultural societies'(C) 'since'(D) 2000 BC. 10. The 'children's'(A) television program 'called'(B) "Sesame Streat" was 'seeing'(C) in 84 countries 'in'(D) 1989. 11. He decided 'doing'(A) the job 'himself'(B) as the 'cost'(C) of repairs to 'his car'(D) was so high. 12. Since 'erecting'(A) in 1886, 'the'(B) Statue of Liberty 'has served'(C) as a 'symbol of'(D) freedom. 13. 'When'(A) I arrived 'at her house'(B), I found that she 'has been'(C) out with her new friend 'without'(D) leaving me a note. 14. The governor, with 'his'(A) wife and children, 'are'(B) at home 'watching'(C) the election 'returns'(D) on television. 15. We 'solved'(A) the problem by 'using'(B) a computer rather than 'to do'(C) it all 'by hand'(D). 16. 'Ice skating'(A) and to go skiing 'are'(B) popular 'winter sports'(C) in 'the'(D) Northern United States. 17. The surgeon examined 'the'(A) patient 'quickly'(B), 'and'(C) then 'the operation was begun'(D). 18. World hunger 'it is'(A) one of the 'most'(B) urgent 'problems'(C) that 'we face'(D) today. 19. Now that 'the'(A) stress of examinations 'are'(B) over, we 'can go'(C) somewhere 'for our holiday'(D). 20. The park 'keeper'(A) told US 'not walk'(B) on 'the grass'(C) or we 'would be'(D) fined. 21. Tom didn't 'drive'(A) a car since he 'had'(B) an 'accident'(C) two 'years ago'(D).