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: Any mistake made in the printing of a stamp raises its value to stamp collectors. A mistake on one inexpensive postage stamp has made the stamp worth a million and a half times its original value. The mistake was made more than a hundred years ago in the British colony of Mauritius, a small island in the Indian Ocean. In 1847 an order for stamps was sent to a London printer-Mauritius was to become the fourth country in the world to issue stamps. Before the order was filled and delivered, a ball was planned at Mauritius' Government House, and stamps were needed to send out the invitations. A local printer was instructed to copy the design for the stamps. He accidentally inscribed the words "Post Office" instead of "Post Paid" on the several hundred stamps that he printed. Today there are only twenty-six of these misprinted stamps left fourteen One Penny Orange-Reds and twelve Two Penny Blues. Because of the Two Penny Blue's rareness and age, collectors have paid as much as $16 800 for it.
Answer: was a small island in the Pacific Ocean
Over a century ago, Mauritius _ .

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: The color red often means danger --- and by paying attention, accidents can be prevented. At railroad crossings, flashing red fights warn cars to stay back. A red light at a traffic crossing tells cars to stop, so they don't run into other cars. In the future, the color red also may help prevent danger at construction sites. Thanks to new work by engineers, bridge supports --- or other kinds of materials --- could one day contain a color-changing material. It will turn red before a structure collapses or falls apart. The secret behind the color-changing material is a particular type of molecule . Molecules come in all shapes and sizes, and make up everything you can see, touch or feel. How a molecule behaves depends on what kinds of atoms it contains, and how they're held together. To get a rough picture of one way atoms are held together in a molecule, imagine you and your friends standing in a large circle, holding hands. Each person represents one atom, your clasped hands represent the bond, and the entire circle represents a molecule. The molecule being used to turn the material red is called mechanophore . When one chemical bond in the mechanophore molecule breaks, the rest of the molecule turns red. There is a way to get rid of~ the red color: light. When a bright light is shone on the mechanophore, the broken bond is fixed and the red color disappears. This "self-healing" may be a problem for engineers who want to use the color-changer in big construction projects that will be outside, in the sunlight. And if bright light keeps the red color from appearing, then the mechanophore's warning system will be useless. Scientists still have a lot of work to do before the color-changing molecules can be used outside the lab. If mechanophore can be used in the real world, they are suggested to be employed in a new kind of paint.
Answer: warn people that the building is dangerous
The color red will be used at construction sites to _ .