欢迎访问贝贝英语网！
Oil rigs have to be repaired frequently
and divers, who often have to work in darkness a hundred feet under water,
have been frightened out of their wits by giant fish bumping into them as they work.
Now they have had special cages made to protect them from these monsters.
The fish are not sharks or killer whales, but favourite eating varieties like cod and skate
which grow to unnatural sizes, sometimes as much as twelve feet in length.
Three factors have caused these fish to grow so large:
the warm water round the hot oil pipes under the sea;
the plentiful supply of food thrown overboard by the crews on the rigs;
the total absence of fishing boats around the oil rigs.
