Complete the sentences. Use one of these forms: Present simple
Present continuous
Past simple
Past continuous

Where... (your parents/go) for their holidays last year?
... (you/watch) television very much?
What... (you/do) at 6 o'clock last Sunday morning?
Andy isn't at home very much. He... (go) away a lot.
I... (try) to find a job at the moment. It's very difficult.
I'm tired this morning. I (not/ sleep) very well last night.

1) The properties of building and materials are classified into four groups: physical, mechanical, chemical, technological, etc.

2) Resistance to salt aggression and other chemicals (wood)

An important advantage of natural stone is strength, durability, resistance to environmental influences, frost resistance (stone)

Strength; reliability; versatility; combination with other materials (metal)

3) All metals are divided into two groups: ferrous and non-ferrous

4) Ferrous metals and alloys contain iron, non-ferrous metals do not. Ferrous metals are mild steel, carbon steel, stainless steel, cast iron and wrought iron. ... Since they do not contain iron, non-ferrous metals have a higher resistance to corrosion and rust.

Объяснение: just decided

1)Building materials are divided into natural (natural) and artificial(Строительные материалы разделяют на природные (естественные) и искусственные)

2)Не смогу сказать.

3)metals are divided into two groups: ferrous and non-ferrous(металлы делятся на две группы: черные и цветные)

4)Ferrous metals are those that contain steel and iron.Non-ferrous metals do not contain steel or iron. This group of metals includes: aluminum and copper, Nickel and lead, zinc and tin, brass and gold, silver and platinum, as well as many others that do not contain iron.(Чёрными называются те металлы, которые содержат сталь и железо.Цветные металлы не содержат стали и железа. К данной группе металлов относятся: алюминий и медь, никель и свинец, цинк и олово, латунь и золото, серебро и платина, а так же многие другие, не содержащие железо.)