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 26 to 30.

Mobile phones: a benefit or social nuisance?

Few people under 30 will be able to imagine a time before the existence of mobile phones. Neither will they be (26) ____________ of the harmful effect that many people predicted text language would have on young people's language skills.

Interestingly, linguists nowadays believe that expressing oneself clearly in texts is evidence of a good background in grammar and sentence structure. Mobile phones are credited with encouraging people to communicate more. They can also provide reassurance to people (27) ____________ are alone in dangerous situations. Some people use mobile phones as a kind of barrier to unwelcome social contact; texting can signal your unavailability to (28) ____________ people in the same way that wearing sunglasses and headphones does.

Some issues with mobile phones are still controversial. Talking loudly on the phone while on public transport is thought to be rude and (29) ____________ by many people in the UK. (30) ____________ , a significant minority of people still do it, despite the sighing and other obvious signs of disapproval from their fellow passengers.

(Adapted from "Advanced Expert" by Jan Bell and Roger Gower)