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.

Article: Blue whales are the largest animals ever known to have existed on the planet, and they can grow to a length of 100 feet and weigh more than 330,000 pounds. But recently researchers have found that these whales are on the move and they have migrated (moved) from California waters to areas off Canada and Alaska for the first time since commercial whaling ended in 1965. The researchers identified 15 blue whales that have appeared off the coast of British Columbia and the Gulf of Alaska since 1997. Four of these whales were recognized as ones that were once sighted off California shores, suggesting that the whales are returning to an old migration pattern between the coasts. Before commercial whaling began in the early 1900s, blue whales were found widely throughout the North Pacific and California waters. But from the 1920s to the 1960s, whaling severely reduced the whale populations. Blue whales never recovered in the Northern Pacific, making sightings in this area rare. However, much larger groups of whales have been observed close to California since the 1970s. The scientists had previously thought that the California population was separate from the population that had historically lived in North Pacific waters. But the current study shows that whales off the coast of British Columbia and the Gulf of Alaska are likely part of the California population.[:] To identify the blue whales, the researchers looked at photos of _ taken in the North Pacific Ocean and compared them with a library of blue whale pictures taken along the West Coast of the United States and Southern Pacific. Up to now, the researchers are not quite sure why the whales are changing their migration patterns, but they suspect that the whales may be following their food moving farther north by the changes in ocean conditions.
Answer: moving from the south to the north
According to the passage, blue whales are _ .

Article: If you saw another kid ride her bike too fast around a corner and fall down, you might ride your bike more slowly on that turn. Yes, we humans are very sensitive to others' mistakes. And the same is true for other animals. Animals mess up all the time. They might eat poisonous leaves, fall off a tree or let their prey slip away. By watching others fail, an animal can avoid making the same mistakes, thus improving its chance of survival. Scientists suspected that one part of the brain helps animals process information about others' errors. Cells in that part appear to become more active when a person sees someone else making a mistake. But researchers didn't know whether individual cells in this part of the brain play different roles in _ errors. To investigate the brain's response to errors in more detail, the researchers taught a game to two macaques, a type of monkey. One monkey could press a yellow or green button while the other watched. If the first monkey pressed the right button, the team gave both animals a treat. Every couple of rounds, the two monkeys switched roles. Meanwhile, the scientists monitored individual cells in the animal's brains. When the first monkey messed up the game by pressing the wrong button, a group of cells in the second monkey's brain fired. But if the second monkey also made the wrong choice during its turn, some of the cells in that group didn't respond. Those unresponsive cells reacted specifically to mistakes made by others, not to the monkey's own mistakes. Scientists believe other parts of the brain also might help people process information about another's errors. "You start to think about this other person and see things from his angle. " Ellen de Bruijn, told Science News. She studies the brain at the University of Leiden in the Netherlands.
Answer: others' mistakes
In the experiment mentioned, those unresponsive cells are only sensitive to _ .

Article: The next great land area that man hopes to control is the moon. In size it is nearly equal to the area of North and South America. However, it presents a hostile environment. Temperatures range +120 to -150 degrees Centigrade. There is no air, and no water. Today there is considerable scientific speculation about living on the moon. When man will begin life on the moon surface is still not determined. But experts believe that settlement will take place in three steps. First, there will be increasing periods of exploration with temporary shelters. These periods will be followed by longer stays with housing under the surface of the moon and daily necessities brought by the settlers themselves from the earth. Finally, settlements that are self-supporting will be founded. The main job of the early settlers will be to stay alive. They will have to plant crops under huge domes to produce food and oxygen and find water sources. After this is done, the settlers will have time to explore the possibilities of commercial development and to make discoveries important to science. The characteristics of the moon that make it bad for human staying alive may make it ideal for certain kinds of manufacturing . Operations requiring a vacuum or extreme cold are examples. Therefore, industrial diamonds might be produced on the moon.
Answer: about the same as that of North and South America
The area of the moon is _ .