26. A Most forms of steel abruptly become brittle
27. J ... that resists fractures at much lower temperatures
28. B without the need for expensive additives
29. E providing a lifeline for the besieged British
30. I the ships cracked in the icy north Atlantic
31. N So scientists have strived to find a solution
32. C a more physical approach
33. G that is comparable to that of..
34. H the number of components needed in a construction. Job
35. K by replacing solid supports with hollow tubes