Complete with the correct phrases from the list.

LIVING LONGER

For the first time, science (01)..... that the aging process (02)...... Life expectancy could be doubled. Aging used to be mysterious and now it isn't. It is a problem that has been solved. Scientists say (03)..... in laboratory insects (04)..... the extension of life. They have bred fruit-flies that can live for the equivalent of about 150 human years. They have discovered that a longer-lived fly that (05)..... one particular genetic trait. The genes of what they call "Methuselah" fruit flies contain the recipe for a particularly powerful protein that can neutralise damaging chemicals. These chemicals, known as "free radicals", (06).....: a single atom of oxygen is one example. Free radicals are produced (07)...... They are highly reactive and can tear apart important biological molecules such as DNA. The protein (superoxide dismutase) produced by the Methuselah fruit-flies mops up the free radicals (08)..... their destructive work. All that (09)..... is to move from worms and flies to men, not all that far, and deliver the appropriate gene (10)......

A cause the aging process

B has a greater abundance of

C remains to be done

D which are close

E naturally within the body

F can be slowed down

G will not create difficulties

H so that they cannot perform

I offers a realistic possibility

J inside the system

K to the human system

L that they have identified

M they expect to succeed

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