In this task, you're given an article and an answer. Your task is to generate the fill-in-the-blank question for this answer based on the given article. The blanks are always at the end of the question, and can be filled with more than one word or phrase.
--------
Question: Article: There is a unique place where deserted factories have been transformed into a lively artistic zone - where the city's tradition and heritage  meet with cutting-edge art and fashion. This is Redtory. Located at Yuancun Si Heng Lu, not far from the Pearl River of Guangzhou city, Redtory is a creative cultural and industrial zone made up of more than 30 old buildings - mostly red-brick ones. Back in 1956, it used to be the biggest canning factory in China. The factory produced the Can Dace   with Black Bean Sauce, an iconic food product in the last century, well-known throughout south-east Asia. After the local government's industrial structure reformations, the canning factory moved away and the workshops were left deserted. There was nothing left but memories in well-preserved Soviet-style buildings. Not long after the noise of the running machines was gone, posters of advertisement and art were found hanging on the wall in the area. To enrich the cultural and artistic life of the people in Guangzhou, the abandoned factories reopened in 2009 - displaying art, fashion and culture of different forms. Redtory is home to more than 40 establishments including art galleries, themed restaurants and design studios. Large international cultural exchange activities, art exhibitions and seminars are often held here, attracting hundreds of thousands of visitors every year. Meanwhile, waste materials have been used wisely instead of being thrown away. For instance, some installations  standing around the area are made up of the rusty machines or components from the old canning factory. The shabby and nostalgic  appearance combined with fashionable and artistic features makes Redtory uniquely attractive. That may be the reason that Redtory is considered the holy land for young art-lovers in Guangzhou. Add.: No.128 Yuancun Si Heng Lu, Tianhe District, Guangzhou Bus: Yuancun Er Heng Rd Stop - 40,44,140,284,293,299,401,504,540,542,583,882;Yuancun Stop Terminal (Meilin Garden) - B11,243;Pazhou Bridge (North) Stop - 137,304,564,B7,B25 Metro: Exit B, Yuancun Station, Line 5 
 Answer: the place was intended for other purposes

Answer: The canning factory was removed from Redtory because   _  .


Question: Article: Owning a smart phone may not be as smart as you think. They may let you surf the Internet, listen to music and snap photos wherever you are... but they also turn you into a workaholic  . A study suggests that, by giving you access to emails at all times, the all-singing, all-dancing mobile phone adds as much as two hours to your working day. Researchers found that Britons work an additional 460 hours a year on average as they are able to respond to emails on their mobiles. The study by technology retailer Pixmania, shows the average UK working day is between nine and ten hours, but a further two hours is spent responding to or sending work emails, or making work calls. Almost one in ten admits spending up to three hours outside their normal working day checking work emails. Some workers confess   they are on call almost 24 hours a day, with nine out of ten saying they take work emails and calls outside their normal working hours. Nearly two-thirds say they often check work emails just before they go to bed and as soon as they wake up, while over a third have replied to one in the middle of the night. Ghadi Hobeika, marketing director of Pixmania, said, "The ability to access millions of apps, keep in contact via social networks and take photos and video as well as text and call has made smart phones valuable for many people. However, there are _ . Many companies expect their employees to be on call 24 hours a day, seven days a week, and smart phones mean that people cannot get away from work. The more constantly in contact we become, the more is expected of us in a work capacity  ." 
 Answer: a travel journal

Answer: The text is probably taken from   _  .


Question: Article: A blue hole is a flooded sea cave with a hole that opens up at the land's surface. These cave systems form in carbonate rock, often on islands. Some blue holes have very special rock formations and water chemistry. Far below sea level, they contain some of the harshest environments on Earth, with no oxygen and no light. Yet these areas are filled with life forms that have adapted to the extreme conditions. Information gathered from these blue holes is helping scientists to increase their understanding of biology, archaeology and geology. But exploring these blue hole environments brings danger as well as discovery.  Blue holes get their name from the color1 some have when seen from the air. The color1 is usually a reflection of the sky on the water. But not all of these cave systems have blue surfaces. Some contain dark or muddy water. Blue holes are the result of erosion in which water breaks down rock. Rain falling thousands of years ago contained chemicals which slowly wore away at the limestone landmass. These holes were later filled with sea water as the sea level changed. The rising and falling of sea levels and the mixture of salt and fresh water further wore away at these cave formations. Blue holes are vertical caves. But they can also have horizontal cave formations that may be hundreds of meters long.  These flooded cave systems can be found in the ocean, or they can be found inland. Ocean caves are affected by tides, so they always have water movement. But blue holes on land are very still. They have several layers of water, chemicals, and bacteria. The top layer of fresh water comes from rainfall. This layer acts like a cap on top of the layered mixture, and keeps out oxygen from the atmosphere. The fresh water floats on a denser layer of saltwater. Underneath this is a layer of poisonous hydrogen sulfide, produced by bacteria living in the water. Underneath this layer is anoxic seawater -- water that does not contain any oxygen.  Underwater caves are probably one of the least explored ecosystems on the planet. One reason blue holes have not been fully explored is that they can be extremely dangerous. There are many safety rules that divers must follow to help ensure their survival. First, divers must have training and experience to swim in these caves. Those who explore a cave for the first time must establish a thin rope called a guideline. This line helps them to safely enter and bring more than one set of breathing equipment in case one device fails. Meanwhile, they must pay careful attention to their air supply.  The rule is to use a third of their air to enter the cave, a third to exit, and a third for emergencies.          For most explorers, though, the possibility of discovery in these cave environments makes the experience worth the risk. You can jump into what looks like an insignificant little hole in the ground, and come out with information that's of value to many different disciplines, Scientists are interested in these caves because oxygen-free conditions there are similar to those on Earth long ago, before oxygen existed on our planet., as well as similar to space. 
 Answer: are flooded caves found mostly on islands

Answer:
According to the Passage, blue holes  _  .


