请l阅读 Passage 2，完成第 26 ~ 30小题。

                                                    Passage 2

Texting pedestrians aren't ju8t an annoyance to their fellow walkers,Australian researchers armed with movie special-effects technology have determined scientifically:They're a threat to themselves.Using motion-capture technology similar to that used for films such as"The Hobbit, " University of' Queensland researchers concluded that texting while walking not only affects balance and the ability to walk in a straight line,but can actually damage a texter's posture. "I was checking emails while walking to work this moming," said Wolbert van den Hoom. "But it has a serious influence on the safety of people who type or read text while walking. "Anecdotes back him up. A tourist from Taiwan walked off a port near Melboume last month while checking Facebook-bringing an abrupt,and icy end to a penguin-watching visit. Another shopper in the U.  S. was too addicted to his mobile phone to notice the fountain ahead,walking straight into it.  And as mobile-phone use has grown-to about 77% of the world's population,the study says-so  has the number of phone-related accidents. The number of U. S. emergency-room visits linked to phone use on the move doubled to as many as l,500 between 2005 and 2010,an Ohio State University study recently showed. Authorities world-wide have taken note. Signs on Hong Kong's subway system advise passengers in three languages to keep their eyes off their phones. Police and transport authorities have also wamerd  the danger in Singapore,where the Straits Times newspaper ranked it as" No. 2 Bad Habit" ,due to the rising number of road deaths. Some U. S. states,including New York and Arkansas,are even consider ing bans on this act. The Australian study used 26 volunteers,a third of whom admitted having hit objects while tex- ting. They were fitted with different equipment in different parts of their body,and asked to walk 8.5 meters three times-once without a phone,once while reading a text and once while writing a text-while eight cameras captured the action. Volunteers using the phone walked slower and with shorter steps( and slowest c,f all when typ- ing) ,and,more seriously,they locked their arms and elbows in-like" robots" ,in the researchert'words. That forced their heads to move more,throwing them off balance. "In a pedestrian environment,inability to maintain a straight path would be likely to increase po-tential for hits,falls and traffic accidents,"said Mr. van den Hoorn. "The best thing to do is to step a-side and stop,or keep off the phone. "