Qingdao is _____ most beautiful coastal city and I think I’ll go there for _____ second time.

_____ to nuclear radiation, even for a short time, may produce variants (变异体) of genes in human bodies.

This maths problem is_______ easier but______ interesting than that one.

It was really a________experience.Afterwards everybody was very________. [ ]

Instead of staying the same every day, Mary’s working hours are .