21. Maggie considers that hustle and bustle of New York annoying as she 　　　 in the tranquil countryside.　
(A)was used to live　
(B)used to living　
(C)is used to live　
(D)is used to living

17. Smartphones are rather helpful in many aspects, and, as a result, many 　　　 it difficult to do without one.　 (A)find　 (B)view　 (C)take　 (D)make

18. As more and more species are faced with extinction, how to sustain biodiversity is 　　　 great significance to human beings.　 (A)under　 (B)of　 (C)about　 (D)beyond

19. Learning for her grandfather's death, Sally was struck dumb with tears 　　　 down her cheeks.　 (A)to stream　 (B)stream　 (C)streaming　 (D)streamed

20. Keven, on behalf of his company, successfully signed a contract with a multinational corporation this morning. He 　　　 ecstatic at that moment.　 (A)can't be　 (B)couldn't have been　 (C)must be　 (D)must have been

22. To pay his way through college, Allen takes a couple of part-time jobs, one of 　　　 is tutoring elementary school students.　 (A)it　 (B)that　 (C)which　 (D)them

23. Dying to pass the upcoming exams with flying colors, all Sarah has to do is 　　　.　 (A)sitting up day after day　 (B)work harder for the exams　 (C)to stopping checking her phone so much　 (D)stayed focused on her schoolwork

24. 　　　 as Jason was, he tried hard to repress his overwhelming joy for fear that his opponents thought him arrogant.　 (A)Excited　 (B)Exciting　 (C)Excitement　 (D)Excite

25. When traveling solo in a foreign country, you cannot be 　　　 careful about any stranger getting close to you; that person may be a pickpocket.　 (A)enough　 (B)too　 (C)very　 (D)over

26. Which of the following is NOT mentioned as one of the uses of facial recognition technology?　 (A)Unlocking a smartphone.　 (B)Gaining access to a building.　 (C)Keeping citizens under surveillance.　 (D)Ensuring special treatment for celebrity guests.

27. Which of the following statements is true about the technology?　 (A)Identical twins can be distinguished with this newly developed technique.　 (B)This system fails to identify people of parts of their faces are made unclear.　 (C)The police don't intend to take advantage of it to track suspects and catch criminals.　 (D)Airline passengers should always show their passport to pass through security at any airport.