Составить монолог

Из текста ниже нужно составить монолог ( о базовых терминах в химии) на 12-14 предложений, выбрав самое необходимое. Должен начинаться с « To begin is..» и заканчиваться на « In conclusion…»
(J. В.) Ladies and gentlemen! Let me begin by introducing my­self. I'm John Brown, and I'm going to teach you chem­istry during the first semester. The purpose of today's lecture is to provide an introduction to chemistry. As you probably know, chemistry is an experimental and theoretical science, studying the composition of matter and the changes that take place in it. Let me remind you that chemical changes involve changes in composition of matter, accompanied by energy changes. Physical chang­es involve changes in the position, location, or size of matter without any alteration in its composition. Energy changes may be explained as the liberation or ab­sorption of energy in the form of light, heat, or electrici­ty. Another thing to remember is that all forms of matter, and we'll discuss it in detail in other lectures, consist of either pure substances or mixtures of two or more sub­stances.
Right? What are the building blocks of matter?... Yes, they are elements. And compounds are combinations of elements. Most of the elements are metals and most of them unite with other elements and form compounds. Now, the formation of a compound from simpler sub­stances is known as synthesis. Another process, analysis, is breaking down a compound into simpler substances or elements, and in this way determining its composition. Remember, please, that the composition of a pure sub­stance never changes.
Furthermore, every substance has physical and chemical properties. Physical properties include... what do they include?
(STUDENT)Oh... colour, smell... well, what else?... solubility, density ah... probably hardness... oh, yes and boiling and melt­ing points.
(J. В.) Right. They include colour, smell, solubility, density, hardness, and boiling and melting points. As for chemical properties, they include the behaviour with other materials. Now, a few words about matter. It exists in three states. What are they?
(STUDENT)Ah... solid, liquid, oh, yes, and gas, gaseous state.
(J. В.) Quite true. The solid, the liquid, and the gaseous state. Usually a substance can be transformed from one state to another under the changes of its... what?
(STUDENT)Temperature.
(J. В.) Yes, temperature. Let me conclude by saying that chem­istry is so much a part of our lives that it's very easily taken for granted. Metals, glass, plastics, dyes, paints, drugs, insecticides, plants, paper and a lot more are made of chemicals. Now, do you have any questions? Is every­thing clear?