51.   The unique feature of ergonomics is its emphasis on the characteristics of human operators and their relevance to the design of work.

52.   Their facial features are indistinguishable, brightly lit though they are by harsh artificial lights.

53.   Then she saw that that was not quite right, because their features were very different.

54.   There were various features of the role of the military in Soviet politics that are striking to the Western observer.

55.   These features are probably reflections of the degree of leaching, which depends to a large extent on the rainfall.

56.   These included some engineering schemes such as bridges and tunnels, but the most interesting feature was undoubtedly the hierarchy of networks.

57.   This feature is incredibly useful and it is a vital part of racing technique.

58.   This feature is of particular interest if a radical revision is suggested by the evaluation.