Chia dạng đúng của từ trong ngoặc

1.if it doesn't rain soon,there'll be a                 of water (SHORTR)
2THey haven't found the                    to his problem yet (SOLVE)
3.we are talking about the preser vation of                     resources(NATURE)
4.The plane arrived at the airport                  after a violent storm (SAFE)
5.you look tired .I think you should                   for a while (RELAXATION)