Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.
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Question: Context: People all over the world today are beginning to hear and learn more and more about the problem of pollution.Pollution is caused either by man's release of completely new artificial substances into the environment,or by releasing greatly increased amounts of a natural substance,such as oil from oil tankers into the sea. The whole industrial process which makes many of the goods and machines we need and use in our daily lives,is bound to create a number of waste products which upset the environmental balance,or the ecological balance as is also known.Many of these waste products can be prevented or disposed of.But while more and more new and complex goods are produced,there will be new,dangerous waste to be disposed of,for example,the waste products from nuclear power stations.Many people,therefore,see pollution as only part of a larger and more complex problem,that is,the whole process of industrial production and consumption of goods.Others again see the problem mainly in connection with agriculture,where new methods are helping farmers grow more and more on their land to feed our ever-increasing population.However,the land itself is gradually becoming worn out as it is being used,in some cases,too heavily,and artificial fertilizers can not restore the balance. Whatever its underlying reasons are,there is no doubt that much of the pollution caused could be controlled if only companies,individuals and governments would make more efforts.In the home there is an obvious need to control litter and waste.Food comes wrapped up three or four times in packages that all have to be disposed of;drinks are increasingly sold in bottles or tins which can not be reused.This not only causes a litter problem,but also is a great waste of resources,in terms of glass,metals and paper.Advertising has helped this process by persuading many of us not only to buy things we neither want nor need,but also to throw away much of what we do buy.Pollution and waste combine to be a problem everyone can help to solve by cutting out unnecessary buying,excessive consumption and careless disposal of the products we use in our daily lives. 
 Question: Many people see pollution as only part of .

Answer: the whole process of industrial production and consumption of goods


Question: Context: Ways to travel Modern life is impossible without travelling. The fastest way to travel is by air. With a modern plane you can travel in one day to places which took a month or more one hundred years ago. Travelling by train is slower than by air, but it has its advantages . You can see the country you are travelling in. Modern trains have comfortable seats and dining cars. They make even the longest journey enjoyable. Some people prefer to travel by sea when it is possible. There are large lines and river boats with which you can visit many other countries and different places. Travelling by sea is a very pleasant way to spend a holiday. Many people like to travel by car. You can make your own timetable. You can travel three or four hundred miles or only fifty miles a day, just as you like. You can stop wherever you wish: where there is something interesting to see, at a good restaurant where you can enjoy a good meal, or a hotel to spend the night. That is why travelling by car is popular for pleasure trips, while people usually take a train or a plane when they are travelling on business. 
 Question: How many ways to travel are mentioned in the passage?

Answer: four


Question: Context: A proton is one of three main particles that make up the atom. The other two particles are the neutron and electron. Protons are found in the nucleus of the atom. This is a tiny, dense region at the center of the atom. Protons have a positive electrical charge of one (+1) and a mass of 1 atomic mass unit (amu), which is about 1.67 1027 kilograms. Together with neutrons, they make up virtually all of the mass of an atom. Click image to the left or use the URL below. URL: Q: How do you think the sun is related to protons? A: The suns tremendous energy is the result of proton interactions. In the sun, as well as in other stars, protons from hydrogen atoms combine, or fuse, to form nuclei of helium atoms. This fusion reaction releases a huge amount of energy and takes place in nature only at the extremely high temperatures of stars such as the sun. All protons are identical. For example, hydrogen protons are exactly the same as protons of helium and all other elements, or pure substances. However, atoms of different elements have different numbers of protons. In fact, atoms of any given element have a unique number of protons that is different from the numbers of protons of all other elements. For example, a hydrogen atom has just one proton, whereas a helium atom has two protons. The number of protons in an atom determines the electrical charge of the nucleus. The nucleus also contains neutrons, but they are neutral in charge. The one proton in a hydrogen nucleus, for example, gives it a charge of +1, and the two protons in a helium nucleus give it a charge of +2. Protons are made of fundamental particles called quarks and gluons. As you can see in the Figure 1.1, a proton contains three quarks (colored circles) and three streams of gluons (wavy white lines). Two of the quarks are called up quarks (u), and the third quark is called a down quark (d). The gluons carry the strong nuclear force between quarks, binding them together. This force is needed to overcome the electric force of repulsion between positive protons. Although protons were discovered almost 100 years ago, the quarks and gluons inside them were discovered much more recently. Scientists are still learning more about these fundamental particles. 
 Question: the atoms of different elements have

Answer:
different numbers of protons.