3. Combine the names of different hydrocarbon compounds (given in the left column) with their structural definitions (in the right column).

   alkenes; alkynes; aromatics; benzene; diens; dicycloparaffines (bicycloalkanes); gases, paraffin waxes; heavy fractions; monocycloparaffines (monocycloalkanes); naphthalene; naphthenes; polynuclear aromatics.

   a single-ring aromatic compound; straight-chain molecules; branched-chain molecules; compounds with one carbon-carbon double bond; compounds with carbon-carbon triple bond; compounds with three or more fused aromatic rings; compounds with two carbon-carbon double bond; fused double-ring aromatic compound; saturated cyclic compounds; single ring naphthenes; two-ring naphthenes; unsaturated cyclic compounds.

4. Read, translate and define what parts of speech the words and their derivatives belong to. Write out and memorize those that are new for you.

Alternate – alternately – alternating – alternation – alternative; form – formula – formulae– formulate; fuse– fused– fusibility– fusible– fusing– fusion; predominance– predominant– predominate– predominately– predominating; saturability – saturable – saturant– saturate– saturated– saturation– unsaturated; valence – valency – valent.

5. Read the meanings of the word alternate and its synonymic derivatives and translate the given sentences. State what part of speech they belong to.

1. alternate [ɔːl'tɜːnət], alternative – альтернатива; замена, заместитель.

2. alternate [ɔːl'tɜːnət], alternating, alternative – 1) (по)переменный, чередующийся; 2) запасный; дополнительный, запасной, резервный.

3. alternate ['ɔːltəneɪt] – 1) сменять друг друга; чередоваться; 2) колебаться.

1. A particular feature (характерная черта) of the hydrocracking process, as compared with its alternatives, is its flexibility (гибкость) and high quality of its products. There are also examples where hydrocracking is complementary rather than alternative to the other conversion process.

2. Other solvents that are used include benzene, methyl isobutyl ketone, propane, petroleum naphtha, ethylene dichloride, methylene chloride, and sulfur dioxide. In addition, there is a catalytic process used as an alternate to solvent dewaxing.

3. The benzene molecule has six carbon atoms with alternate double and single bonds joining them and with one hydrogen atom bound to each carbon atom.

4. When double bonds alternate with single in a chain they are called conjugated (сопряженный) double bonds.

6. Translate the following sentences paying attention to compound conjunction (составной союз) either … or – или … или; and the word either – любой, оба, каждый, тот или другой; один из двух.

1. Either of aromatics reacts readily because it has carbon atoms that are deficient in hydrogen.

2. However, paraffinic hydrocarbons are usually only a small part of the heavy petroleum residues (остатки), the rest being cyclic hydrocarbons, either aromatic or naphthenic in character.

3. Solvent dewaxing is used to remove wax from either distillate or residual (остаточный) base stocks at any stage in the refining process.

4. The polymer can then exist in either of two configurations with the linkage of the carbon atoms 1 and 4 either on the same side of the plane of the new double bond (cis-configuration) or on opposite sides (trans-configuration).