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: There are many places around the city and online to buy Las Vegas show tickets. With dozens of websites you can find at home, ticket box offices, Tix 4 Tonight (one of the two half-price ticket sellers) locations, and ticket sellers along the Las Vegas trip, you might wonder where you could find your best deal. Major Shows If you want to see one of the top shows in Las Vegas, you could buy your tickets online before your trip. Many of these shows sell out months ahead of time, so make sure you do your research. Best Place to Buy Discounted Tickets If you want discounted tickets for Las Vegas shows, you should go to one of the four Tix 4 Tonight locations. These locations get tickets early in the morning or throughout the day if shows are not sold out. Do not expect to find discounted tickets here for the hottest shows in town such as one-night concerts or shows like Celine Dion's. These seldom make their way to Tix 4 Tonight. Coupon books As you walk along the Las Vegas Strip, you are going to come across people handing out the Vegas Values coupon books or other coupons. These may help you find discounted coupons for various shows around town. Tickets bought with coupons have to be bought at the box office for the show. These are usually located near the theater used for the show. On-Strip Sellers If you see people standing on the Strip selling show tickets, make sure you avoid them. While a few of these sellers might be legitimate ,they often cheat people by selling counterfeit tickets. Catching a show in Las Vegas is one of the various activities people take part in every single day. While there is not one set place to be the best to buy tickets, make sure you get to see the show you want.
Answer: through online shopping
If you want to see Celine Dion's performance, you should buy the tickets _ .

Article: In a very real sense, people who have read good literature have lived more than people who cannot or will not read. To have read Gulliver's Travels is to have had the experience of listening to Jonathan Swift, of learning about man's cruelty to man. To read Huckleberry Finn is to feel what it is like to drift down the Mississippi River on a raft . To have read Byron is to have suffered his rebellions with him and to have enjoyed his nose--thumbing at (......) society. To have read Native Son is to know how it feels to be frustrated in the particular way in which Blacks in Chicago are frustrated. This is _ communication. It enables us to feel how others felt about life, even if they lived thousands of miles away and centuries age. It is not true that "We have only one life to live." If we read, we can live as many more lives and as many kinds of lives as we wish.
Answer: reading broadens a person's experience
The sentence "People who have read good literature have lived more than people who cannot or will not read" suggests that _ .

Article: A dense wave of smog began in the Chinese city of Harbin and the surrounding Heilongjiang, Jilin, and Liaoning Provinces on 20 October 2013. Unseasonably warm temperatures with very little wind across northeastern China coincided with the smoke from local farmers' burning straws and the start-up of Harbin's coal-powered central heating system. Record densities of fine particulates were measured in the city. In Harbin, the levels of PM2.5 (particulate matter) rise to 1,000 micrograms per cubic meter, worse than Beijing's historic highs. Visibility was reduced to below 50m in parts of Harbin, and below 500m in most of the neighbouring Jilin Province. On Fa Yuen Street in Harbin, visibility of less than 5m was reported. The smog reduced after October 23, 2013 and completely broke up on October 28, 2013 by the first local snow and icy rain due to a cold front moving in from Russia. Harbin lies in the north of China where winter temperatures can drop to -40degC, demanding a six-month heating season. Daily particulate levels of more than 40 times the World Health Organization recommended maximum level were reported in parts of Harbin. The smog remained till 23 October, when almost all monitoring stations in Heilongjiang, Jilin,and Liaoning Provincesreported readings above 200mg/m3forPM2.5. PM2.5 is the amount of particulate matter less than 2.5 micrometers in diameter in the air, with the WHO recommending a maximum 24-hour mean of 25 micrograms per cubic meter (mg/m3). On the morning of 25 October, PM2.5 measurements in Harbin had fallen to an average of 123mg/m3. All highways in the surrounding Heilongjiang Province were closed. In Harbin, all primary and middle schools were closed for three days and authorities stopped flights at the airports. Hospitals reported a 23 percent increase in admissions for breathing problems. However, this smog will have no influence on Harbin Ice Festival events later in December 2013. Air pollution in Chinese cities is of increasing concern to China's leadership. Particulates in the air can affect human health and also have influences on climate and rainfall. Pollution from the burning of coal has reduced life expectancy by 5.5 years in the north of China, as a result of heart and lung diseases.
Answer: the start-up of heating system
One cause of the heavy smog in the northeastern Chinese cities may be _ .