Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 31 to 35.

Not everybody recognizes the benefits of new developments in communications technology. Indeed, some people fear that text messaging may actually be having a negative ______(31) on young people's communication and language skills, especially when we hear that primary school children may be at ______(32) of becoming addicted to the habit. So widespread has texting become, however, that even pigeons have started doing it. What‟s more, in this case, it's difficult to view the results as anything but positive.

Twenty of the birds are about to ______(33) to the skies with the task of measuring air pollution, each ______(34) with sensor equipment and a mobile phone. The ______(35) made by the sensors will be automatically ______(36) into text messages and beamed to the Internet - where they will appear on a dedicated 'pigeon blog'.

Đáp án đúng là: C
Giải thích
be at risk of sth/V-ing: có nguy cơ (làm) gì
“...especially when we hear that primary school children may be at risk of becoming addicted to the habit.”
(... đặc biệt là khi ta nghe được rằng trẻ em học tiểu học có nguy cơ trở nên nghiện thói quen đó.)