The Old Gate In the Middle Ages the vast majority of European cities bad walls around them. This was partly for defensive 1 but another factor was the need to keep out anyone regarded as undesirable, like people with contagious 2 . The Old City of London gates were all 3 by the end of the 18th century. The last of London’s gates was removed a century ago, but by a 4 of luck, it was never destroyed. This gate is, in 5 fact, not called a gate at all; its name is Temple Bar, and it marked the 6 between the Old City of London and Westminster. In 1878 the Council of London took the Bar down, numbered the stones and put the gate in 7 because its design was 8 it was expensive to 9 and it was blocking the traffic. The Temple Bar Trust was 10 in the 1970’s with the intention of returning the gate home. The aim of the trust is the 11 of the nation’s architectural heritage. Transporting the gate will mean physically pulling it 12 , stone by stone, removing and rebuilding it near St Paul’s Cathedral. Most of the facade of the gate will probably be 13 , though there is a good 14 that the basic structure will be sound. The hardest 15 of all, however, will be to recreate the statues of the monarchs that once stood on top of the gate.
A. requirement
B. job
C. necessity
D. obligation
Pool Watch Swimmers can drown in busy swimming pools when lifeguards fail to notice that they are in trouble. The Royal Society for the Prevention of Accidents says that on average 15 people drown in British pools each year, hut many more suffer major injury after getting into difficulties. Now a French company has developed an artificial intelligence system called Poseidon that sounds the alarm when it sees someone in danger of drowning. When a swimmer sinks towards the bottom of the pool, the new system sends an alarm signal to a poolside monitoring station and a lifeguard’s pager. In trials at a pool in Ancenis, near Nantes, it saved a life within just a few months, says Alistair McQuade, a spokesman for its maker, Poseidon Technologies. Poseidon keeps watch through a network of underwater and overheard video cameras. AI software analyses the images to work out swimmers trajectories. To do this reliably, it has to tell the difference between a swimmer and the shadow of someone being cast onto the bottom or side of the pool. "The underwater environment is a very dynamic one, with many shadows and reflections dancing around." says McQuade. The software does this by "projecting" a shape in its field of view onto an image of the far wail of the pool. It does the same with an image from another camera viewing the shape from a different angle. If the two projections are in the same position, the shape is identified as a shadow and is ignored. But if they are different, the shape is a swimmer and so the system follows its trajectory. To pick out potential drowning victims, anyone in the water who starts to descend slowly is added to the software’s "pre-alert" list, says McQuade. Swimmers who then stay immobile on the pool bottom for 5 seconds or more are considered in danger of drowning. Poseidon double-checks that the image really is of a swimmer, not a shadow, by seeing whether it obscures the pool’s floor texture when viewed from overhead. If so, it alerts the lifeguard, showing the swimmer’s location on a poolside screen. The first full-scale Poseidon system will be officially opened next week at a pool in High Wycombe, Buckinghamshire. One man who is impressed with the idea is Travor Baylis, inventor of the clockwork radio. Baylis runs a company that installs swimming pools, and he was once an underwater escapologist with a circus. "I say full marks to them if this works and can save lives," he says. But he adds that any local authority spending £30,000-plus on a Poseidon system ought to be investing similar amounts in teaching children to swim. Which of the following statements about Trevor Baylis is NOT true
A. He runs.
B. He invented the clockwork radio.
C. He was once an entertainer.
D. He runs a company.