There are three main groups of oils: animal, vegetable and mineral.. f8 k# j2 p) G U
Great numbers of animal oil come from whales, those enormous __1__
+ e% S8 g k j creatures of the sea which are the largest remaining animals in the: I% }; J+ A. q$ t* M" R
world. To protect the whale from the cold of the Arctic seas, nature
1 b% a: e- a7 g has provided it with a thick cover of fat called blubber. When the __2__
8 x$ e& d& l3 {; m7 M% a( ? whale is killed, the blubber is stripped off and boiled down, either% g- {8 H! t* X+ l! ]- s
board the ship or on shore. It produces a great quantity of oil which __3__$ Y. Z9 d d5 O2 K& B+ S
can be made into food for human consumption. A few other creatures; Z! F# S5 U- k- Y+ r( p- v
yield oil, and none so much as the whale. The livers of the cod and __4__) z' ^- T. y0 ?
the halibut, two kinds of fish, yield nourishing oil.: U# J7 F/ C( B# E) m0 @) d# ?/ e
Both cod liver oil and halibut liver oil are given to sick children
& `7 y. I4 I% ^' J. ]1 N, x6 ] and other invalids who need certain vitamins. These oils may be, j: d% n( T; K) _1 R8 O' I
bought at any chemist. Vegetable oil has been known from antiquity. __5__
1 O7 _: t8 b& F No household can not get on without it, for it is used in cooking. To __6__
' C% C/ l0 { J1 P9 I( [ the ordinary man, one kind of oil may be as important as another.% E% m3 t3 S8 B
But when the politician or the engineer refers to oil, one almost always __7__
: r5 g8 K, z/ @, d8 M1 X+ W means mineral oil, the oil that drives tanks, aeroplanes and warships,
6 x _4 e8 B* g* F Y/ M- l2 p. U motor-cars and diesel locomotives; the oil that is used to lubricate
/ W0 t0 |, }9 q$ ^# _; M3 i all kinds of machineries. This is the oil that has changed the life __8__' ~# O4 A0 h1 W# [: m9 S. {
of the common men. To it we owe the existence of the motor-car, __9__
6 u8 [4 n4 g' C+ [ which has replaced the private horse-drawing carriage. __10__ |
发表于 2012-8-14 11:29:10
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