The word “these" is the first passage refers to_________

Experts in climatology and other scientists are becoming extremely concerned about the changes to our climate which are taking place. Admittedly, climate changes have occurred on our planet before. For example, there have been several ice ages or glacial periods. These climatic changes, however, were different from the modern ones in that they occurred gradually and, as far as we know, naturally. The changes currently being monitored are said to be the result not of natural causes, but of human activity. Furthermore, the rate of change is becoming alarmingly rapid. The major problem is that the planet appears to be warming up. According to some experts, this warming process, known as global warming, is occurring at a rate unprecedented in the last 10,000 years. The implications for the planet are very serious. Rising global temperatures could give rise to such ecological disasters as extremely high increases in the incidence of flooding and of droughts. These in turn could have a harmful effect on agriculture. It is thought that this unusual warming of the Earth has been caused by so-called greenhouse gases, such as carbon dioxide, being emitted into the atmosphere by car engines and modern industrial processes, for example. Such gases not only add to the pollution of the atmosphere, but also create a greenhouse effect, by which the heat of the sun is trapped. This leads to the warming up of the planet. Politicians are also concerned about climate change and there are now regular summits on the subject, attended by representatives from around 180 of the world’s industrialized countries. Of these summits, the most important took place in Kyotoin Japanin 1997. There it was agreed that the most industrialized countries would try to reduce the volume of greenhouse gas emissions and were given targets for this reduction of emissions. It was also suggested that more forests should be planted to create so-called sinks to absorb greenhouse gases. At least part of the problem of rapid climate change has been caused by too drastic deforestation. Sadly, the targets are not being met. Even more sadly, global warnings about climate changes are often still being regarded as scaremongering. 

According to the passage, in what way did the climate changes in the ice ages differ from the modern ones?

Which is the most popular sport in the US?

My family consists of four people. There's my father whose name is Jan, my mother whose name is Marie, my brother, Peter and of course, me. I have quite a large extended family as well but, only the four of us live together in our apartment in a block of flats. My father is fifty-two years old. He works as an accountant in an insurance company. He is tall and slim, has got short brown and gray hair and blue eyes. My father likes gardening very much as well as listening to music and reading books about political science. His special hobbies are bird watching and travelling. Now I’ll describe my mother and my brother. My mother is fortyseven and she works as a nurse in a hospital. She is small, and slim, has short brown hair and green eyes. She likes bird watching and travelling too, so whenever my parents are able to they go someplace interesting for nature watching. Since we have a cottage with a garden they both spend a lot of time there. My brother is sixteen. He is slim and has short brown hair and blue eyes. He also attends high school. He is interested in computers and sports like football and hockey. He also spends a lot of time with his friends. I have only one grandmother left still living. She is in pretty good health even at the age of seventyeight so she still lives in her own flat. I enjoy spending time with her when I can. Both my grandfathers died from cancer because they were smokers, which was really a great tragedy because I didn't get chance to know them. My other grandmother died just a few years ago. I also have a lot of aunts, uncles, and cousins. The cousin I’m closest to is my uncle’s daughter Pauline. We have a lot in common because we are both eighteen and so we are good friends. My parents have assigned me certain duties around the house. I don't mind helping out because everyone in a family should contribute in some way. I help with the washing up, the vacuuming and the shopping. Of course I also have to help keep my room tidy as well. My brother is responsible for the dusting and mopping. He also has to clean his own room. Even though my brother and I sometimes fight about who has to do what job, we are still very close. I am also very close to my parents and I can rely on them to help me. My parents work together to keep our home well maintained and it seem they always have a project or another that they are working on. They respect each other's opinions and even if they disagree they can always come to a compromise. I hope in the future that 1 have a family like ours. 

What does the writer's father do?

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 of 1066. Until the 1600s, English was, for the most part, spoken only in England and had not extended even as far as two centuries, 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 English. Two thirds of the world’s science writing is in English, and English is the main language of technology, advertising, media, international airports, and air traffic controllers. Today there are more than 700 million English users in the world, and over half of these are nonnative speakers, constituting the largest number of non-native users than any other language in the world..

How did children feel when viewing a special series of 15-minute program at school?

Ever since humans have inhabited the earth, they have made use of various forms of communication. Generally, this expression of thoughts and feelings has been in the form of oral speech. When there is a language barrier, communication is accomplished through sign language in which motions stand for letters, words and ideas. Tourists, the deaf, and the mute have no resort to this form of expression. Many of these symbols of the whole words are very picturesque and exact and can be used internationally: spelling, however, can not. Body language transmits ideas or thoughts by certain actions, either intentionally or unintentionally. A wink can be a way of flirting or indicating that the party is only joking. A nod signifies approval, while shaking the head indicates a negative reaction. Other forms of nonlinguistic language can be found in Braille (a system of raised dots read with fingertips), signal flags, Morse code, and smoke signals. Road maps and picture signs also guide, warn and instruct people. While verbalization is the most common form of language, other systems and techniques also express human thoughts and feelings. 

Which of the following best summarizes this passage?

What is the main idea of the passage?