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.

[Q]: Context: To understand minerals, we must first understand matter. Matter is the substance that physical objects are made of. The basic unit of matter is an atom. At the center of an atom is its nucleus. Protons are positively charged particles in the nucleus. Also in the nucleus are neutrons with no electrical charge. Orbiting the nucleus are tiny electrons. Electrons are negatively charged. An atom with the same number of protons and electrons is electrically neutral. If the atom has more or less electrons to protons it is called an ion. An ion will have positive charge if it has more protons than electrons. It will have negative charge if it has more electrons than protons. An atom is the smallest unit of a chemical element. That is, an atom has all the properties of that element. All atoms of the same element have the same number of protons. A molecule is the smallest unit of a chemical compound. A compound is a substance made of two or more elements. The elements in a chemical compound are always present in a certain ratio. Water is probably one of the simplest compounds that you know. A water molecule is made of two hydrogen atoms and one oxygen atom (Figure 3.2). All water molecules have the same ratio: two hydrogen atoms to one oxygen atom. A mineral is a solid material that forms by a natural process. A mineral can be made of an element or a compound. It has a specific chemical composition that is different from other minerals. One minerals physical properties differ from others. These properties include crystal structure, hardness, density and color. Each is made of different elements. Each has different physical properties. For example, silver is a soft, shiny metal. Salt is a white, cube- shaped crystal. Diamond is an extremely hard, translucent crystal. Minerals are made by natural processes. The processes that make minerals happen in or on the Earth. For example, when hot lava cools, mineral crystals form. Minerals also precipitate from water. Some minerals grow when rocks are exposed to high pressures and temperatures. Could something like a mineral be made by a process that was not natural? People make gemstones in a laboratory. Synthetic diamond is a common one. But that stone is not a mineral. It was not formed by a natural process. A mineral is an inorganic substance. It was not made by living organisms. Organic substances contain carbon. Some organic substances are proteins, carbohydrates, and oils. Everything else is inorganic. In a few cases, living organisms make inorganic materials. The calcium carbonate shells made by marine animals are inorganic. All minerals have a definite chemical makeup. A few minerals are made of only one kind of element. Silver is a mineral made only of silver atoms. Diamond and graphite are both made only of the element carbon. Minerals that are not pure elements are made of chemical compounds. For example, the mineral quartz is made of the compound silicon dioxide, or SiO2 . This compound has one atom of the element silicon for every two atoms of the element oxygen. Each mineral has its own unique chemical formula. For example, the mineral hematite has two iron atoms for every three oxygen atoms. The mineral magnetite has three iron atoms for every four oxygen atoms. Many minerals have very complex chemical formulas that include several elements. However, even in more complicated compounds, the elements occur in definite ratios. Minerals must be solid. For example, ice and water have the same chemical composition. Ice is a solid, so it is a mineral. Water is a liquid, so it is not a mineral. Some solids are not crystals. Glass, or the rock obsidian, are solid but not crystals. In a crystal, the atoms are arranged in a pattern. This pattern is regular and it repeats. Figure 3.3 shows how the atoms are arranged in halite (table salt). Halite contains atoms of sodium and chlorine in a pattern. Notice that the pattern goes in all three dimensions. The pattern of atoms in all halite is the same. Think about all of the grains of salt that are
Question: smallest particle of an element that has all the elements properties
[A]: atom

[Q]: Context: Do you know what your blood type is? Maybe you have heard people say that they have type A or type O blood. Blood type is a way to describe the type of antigens, or proteins, on the surface of red blood cells (RBCs). There are four blood types; A, B, AB, and O. 1. Type A blood has type A antigens on the RBCs in the blood. 2. Type AB blood has A and B antigens on the RBCs. 3. Type B has B antigens on the RBCs. 4. Type O does not have either A or B antigens. The ABO blood group system is important if a person needs a blood transfusion. A blood transfusion is the process of putting blood or blood products from one person into the circulatory system of another person. The blood type of the recipient needs to be carefully matched to the blood type of the donor. Thats because different blood types have different types of antibodies, or proteins, released by the blood cells. Antibodies attack strange substances in the body. This is a normal part of your immune response, which is your defense against disease. For example, imagine a person with type O blood was given type A blood. First, what type of antibodies do people with type O blood produce? They produce anti-A and anti-B antibodies. This means, if a person with type O blood received type A blood, the anti-A antibodies in the persons blood would attack the A antigens on the RBCs in the donor blood ( Figure 1.1). The antibodies would cause the RBCs to clump together, and the clumps could block a blood vessel. This clumping of blood cells could cause death. A person with type O blood has A and B antibodies in his/her plasma; if the person was to get type A blood instead of type O, his/her A antibodies would attach to the antigens on the RBCs and cause them to clump together. People with type A blood produce anti-B antibodies, and people with type B blood produce anti-A antibodies. People with type AB blood do not produce either antibody. The second most important blood group system in human blood is the Rhesus (Rh) factor. A person either has, or does not have, the Rh antigen on the surface of their RBCs. If they do have it, then the person is positive. If the person does not have the antigen, they are considered negative. Recall that people with type O blood do not have any antigens on their RBCs. As a result, type O blood can be given to people with blood types A, B, or AB. If there are no antigens on the RBCs, there cannot be an antibody reaction in the blood. People with type O blood are often called universal donors. The blood plasma of AB blood does not contain any anti-A or anti-B antibodies. People with type AB blood can receive any ABO blood type. People with type AB blood are called universal recipients because they can receive any blood type. The antigens and antibodies that define blood type are listed as follows ( Table 1.1). Blood Type Antigen Type Plasma Antibodies A B AB O A B A and B none anti-B anti-A none anti-A, anti-B Can Receive Blood from Types A,O B,O AB, A, B, O O Can Donate Blood to Types A, AB B, AB AB AB, A, B, O
Question: a person with blood type a can receive blood from
[A]: a and o.

[Q]: Context: The Lambro (Western Lombard: Lamber or Lambar) is a river of Lombardy, northern Italy, a left tributary of the Po.
Question: What river is Lambro a tributary of?
[A]:
po