I. Study the words

Tofu is unfermented soya-bean curd, a food with a soft cheeselike consistency made from soya-bean milk.

II. What substances are vital important for living things? What food is rich in these substances?

Protein – any of a large group of nitrogenous compounds of high molecular weight that are essential constituents of all living organisms. They consist of one or more chains of amino acids linked by peptide bonds and are folded into a specific three-dimensional shape maintained by further chemical bonding.

Fat – any of a class of naturally occurring soft greasy solids that are esters of glycerol and certain fatty acids. They are present in some plants and in the adipose tissue of animals, forming a reserve energy source, and are used in making soap and paint and in the food industry.

Carbohydrate [,ka:bəu`haidrəit] – any of a large group of organic compounds, including sugars, such as sucrose, and polysaccharides, such as cellulose, glycogen, and starch, that contain carbon, hydrogen, and oxygen, with the general formula C_m(H₂O)_n: an important source of food and energy for animals.