The word "they" in paragraph 2 refers to .................

What did the professor learn from the study?

The reason why telecommuting has not become popular is that the employees ............

What is the main idea of this passage?

The word -lethal‖ in the second paragraph probably means ............

The word "drastically" in line 21 is closest in meaning to ..........

The rules of etiquette in American restaurants depend upon a number of factors the physical location of the restaurant, e.g., rural or urban; the type of restaurant, e.g., informal or formal; and certain standards that are more universal. In other words, some standards 5 of etiquette vary significantly while other standards apply almost anywhere. Learning the proper etiquette in a particular type of restaurant in a particular area may sometimes require instruction, but more commonly it simply requires sensitivity and experience. For example, while it is acceptable to read a magazine in a coffee shop, it is 10 inappropriate to do the same in a more luxurious setting. And, if you are eating in a very rustic setting it may be fine to tuck your napkin into your shirt, but if you are in a sophisticated urban restaurant this behavior would demonstrate a lack of manners. It is safe to say, however, that in virtually every restaurant it is unacceptable 15 to indiscriminately throw your food on the floor. The conclusion we can most likely draw from the above is that while the types and locations of restaurants determine etiquette appropriate to them, some rules apply to all restaurants. 

What topic is this passage primarily concerned?

The word "somewhat" in the last paragraph could best be replaced by ...........

The first to support the equality of the sexes was .................

For many people who live in cities, parks are an important part of the landscape. They provide a place for people to relax and play sports, as well as a refuge from the often harsh environment of a city. What people often overlook is that parks also provide considerable environmental benefits. One benefit of parks is that plants absorb carbon dioxide—a key pollutant—and emit oxygen, which humans need to breathe. According to one study, an acre of trees can absorb the same amount of carbon dioxide that a typical car emits in 11,000 miles of driving. Parks also make cities cooler. Scientists have long noted what is called the Urban Heat Island Effect: building materials such as metal, concrete, and asphalt absorb much more of the sun’s heat and release it much more quickly than organic surfaces like trees and grass. Because city landscapes contain so much of these building materials, cities are usually warmer than surrounding rural areas. Parks and other green spaces help to mitigate the Urban Heat Island Effect. Unfortunately, many cities cannot easily create more parks because most land is already being used for buildings, roads, parking lots, and other essential parts of the urban environment. However, cities could benefit from many of the positive effects of parks by encouraging citizens to create another type of green space: rooftop gardens. While most people would not think of starting a garden on their roof, human beings have been planting gardens on rooftops for thousands of years. Some rooftop gardens are very complex and require complicated engineering, but others are simple container gardens that anyone can create with the investment of a few hundred dollars and a few hours of work. Rooftop gardens provide many of the same benefits as other urban park and garden spaces, but without taking up the much-needed land. Like parks, rooftop gardens help to replace carbon dioxide in the air with nourishing oxygen. They also help to lessen the Urban Heat Island Effect, which can save people money. In the summer, rooftop gardens prevent buildings from absorbing heat from the sun, which can significantly reduce cooling bills. In the winter, gardens help hold in the heat that materials like brick and concrete radiate so quickly, leading to savings on heating bills. Rooftop vegetable and herb gardens can also provide fresh food for city dwellers, saving them money and making their diets healthier. Rooftop gardens are not only something everyone can enjoy, they are also a smart environmental investment.

According to the author, one advantage that rooftop gardens have over parks is that they ................

Over the past 600 years, English has grown from a language of few speakers to become the dominant language of international communication. English as we know it today emerged around 1350, after having incorporated many elements of French that were introduced following the Norman invasion off 1066. Until the 1600s, English was, for the most part, spoken only in England and had not expanded even as far as Wales, Scotland, or Ireland. However, during the course of the next two century, English began to spread around the globe as a result of exploration, trade (including slave trade), colonization, and missionary work. Thus, small enclaves of English, speakers became established and grew in various parts of the world. As these communities proliferated, English gradually became the primary language of international business, banking, and diplomacy. Currently, about 80 percent of the information stored on computer systems worldwide is in English. Two thirds of the world's science writing is in English, and English is the main language of technology, advertising, media, international airport, and air traffic controllers. Today there are more than 700 million English users in the world, and over half of these are non- native speakers, constituting the largest number of non-native users than any other language in the world. 

What is the main topic of the passage?