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: Until a few months ago, he was a butler in one of the more expensive residential buildings in Manhattan. But now, Nepal-born Indra Tamang is the owner of two multi-million dollar apartments in the same building. The former owner - his former employer, Ruth Ford - died last year and left the apartments to Mr Tamang in her will. Mr Tamang is happy but quickly points out that his good fortune did not come easily. "I am happy and have been touched by the generosity of the Ford family," he says. "I never expected that I will be given the ownership of these apartments. But I have been working for the family for the last 36 years, devotedly, with honesty and dedication . So my hard work has been rewarded." Mr Tamang was 21 when he was brought from Nepal by Charles Ford, a writer and a photographer. Mr Ford died in 2002; his sister, actress Ruth Ford, then took charge and told Mr Tamang that he was like a brother to her after Charles's death. Mrs Ford died aged 98. During the last five years of her life, she lost her eyesight and also developed speech problems. Mr Tamang looked after her most of the time and took care of her medicines and food. He also worked with Charles Ford on various photography projects, which he now wants to keep as the photographer's legacy . He hopes to organize exhibitions of Mr Ford's photographs and edit a book of his works. Mr Tamang plans to sell the bigger, three-bedroom apartment to pay the taxes he owes to the government on his legacy. He says: "The rules of the building might be a problem, as they require a minimum monthly income to qualify to live as owner of apartments. I have my small house here but I am happy with it," Mr Tamang has learnt his lesson from the life of his employers and plans to use his money with great caution. "I think one should save money for old age. That's when you need it the most to get care," he says.
Answer: a reward
Mr Tamang treated the legacy as _ .

Article: Keep it in the air: The Chaoyang Theater is one of the Beijing theaters to present acrobatics all year round. Top acrobatic artists invited from all over the country perform for Chinese and foreign tourists. The program contains trick cycling, leaping through hoops and Chinese magic tricks. Some of the artists have won prizes in international competitions. Time: 7:15 p.m. Daily Place: 36, Dongsanhuan Beilu, Chaoyang District Tel: 1716, 16818 Use your head: Green Hat is a new drama given by a group of young Chinese actors. It's a rewrite of American writer Nathaniel Hawthorne's famous novel The Scarlet Letter. It describes the heroine's great courage in finding the true love against the public disagreement. Time: 7:15 p.m. until March 5, except Mondays Place: China Children's Theater Tel: 102220, 102210 Mix and match: Story of Puppets tells of a fairy, Zixia, who looks for true love in the human world. After watching a puppet play Peony Pavilion, she thinks there must be true love in reality, so she uses magic to turn the puppet characters into humans, wanting to fall in love with the puppet hero. But things don't go as she planned...Li Liuyi, the director of the play has made several successful attempts to present different traditional operas in one play. This time he combines Peking Opera, Kunqu Opera, and Pingju Opera along with a band, using the structure of modem drama. Time: 7:30 p. m. until March 10, except Mondays Place: Small Playhouse of Beijing People's Art Theater Tel: 121118 Peking Opera: The Beijing Peking Opera Troupe will give two performances at the Chang'an Crand Theater. Each performance includes two classical excerpts . One is Wenxi (a play focusing on singing and dancing); the other is Wuxi (a play full of acrobatic dancing). The first night will be The Crossroad and Presenting a Pearl of the Rainbow Bridge. And the second night will see the performance of The Goddess of Heaven Scatte. Place: Chang'an Grand Theater Tel: 813108
Answer: 16818
If a tourist wants to see a performance on March 15, he can call _ to book a ticket.