All of us know the kinds of substances that are know as metals. They are commonly distinguished from other substances by their bright and shiny surfaces. The majority of them are fairly havey.
(a) Since(b)/ Although (c)When
most metals are hard and stong, they
(a) can be (b)/cannot be (c)a
hammered, pulled and pressed inot
various shapes (a)/by mean of (b)/by meaning of (c)/by means of
strong machines. It is more easy to shape
(a)the piece of metal after (b)/that (c) a
it has just been lightly (b)/warmly (c)/now
heated because heat softens it Very great heat
(a) must need to melt a (b)/ been needed (c)/in needed
metal to its liquid (a)/fow. (b)/condition.
(c)/content.
Metal workers always pour the liquid metal
(a) /out of a hollow form
(b)/into
(c) onto
called a mould, usually made of (a)/specialist (b)/ specidied (c)/specially
prepared moulding sand held in a box of wood or iron.
(a) Before the metal (b)/After
(c)/Whil
(a)/has cooled
(b) have cooled
(c) has been cooled
the moulding boxes are broken open and the
(a)/ liquid (b)/ solid (c)/soiled
metal shapes are taken out of the moulds.
(a)/That
(b)/This
(c)/ Thus it
Process is called casting. Metal objects that
(a)/have been fashion
(b) have been fashioned
(c)/are in fashion
by this process break more easily than those made by hammering. When
(a) those (b)/two (c)/all
metals are melted they can be mixed together. The mixture is called an alloy.