A、Their quality has been greatly improved. B、Consumers tend to favor all that is novel. C、Consumers now know much more about tec

The household cleaning products industry really began to take off in the 1950s. Prior to that, resourceful housewives who had grown up in a less prosperous era relied on substances that they used in their kitchens, such as vinegar used to clean windows. Today, the household cleaning products industry is worth billions of dollars a year and is dominated by large global companies.
    In recent years, however, many countries have witnessed a surge in the number of small businesses and companies offering more environment-friendly cleaning products, and they’re doing good business too. One reason for this is that consumers are becoming more aware of environment and sustainability issues. They also want to make their home a safe place free from toxic chemicals. The third reason is people’s awareness of and knowledge about technology has never been greater. In the past, people might have been skeptical of a new product claim to be able to achieve amazing cleaning results, but they now have faith in technology’s ability to do what was once thought impossible.
    There is perhaps no better example of this than a patented cloth sold by one company, which remarkably uses only water rather than traditional cleaning products. The company claims its cloth lifts traps and removes dirt and bacteria. And considering that people don’t see these products in shops or advertised on TV or in the press, it has been a pretty steep rise. Many of the people behind these companies begin testing the viability of their products by selling them at local markets. Then in many cases, customers are doing the marketing for these products by leaving threads of comments on social media praising their virtues. There are also TV shows and books dedicated to maintaining home tidiness and cleanliness, and the benefits of having a clean home. Having a safe and clean home might be one thing people feel they can control in an increasingly out-of-control world. And there are social media celebrities. One woman in Britain has become a social media sensation with more than 2 million followers for her cleaning tips page.
    19.What does the speaker say about the cleaning products industry in recent years?
    20.Why are newly developed cleaning products selling well?
    21.What are some customers doing to help promote nontraditional cleaning products?