insurmountable
adj
(fml 文) (of obstacles, difficulties, etc) that cannot be overcome (指障碍、 困难等)无法超越的, 不能克服的
The problems are not insurmountable. 问题不是无法解决的. Cf 参看 insuperable.
Marine Studio biologists have pointed out that, however intelligent they may be, it is probably a mistake to credit dolphins with any motive of lifesaving.