51. When carbon is added to iron in proper ______the result is steel.

A) rates B) thicknesses C) proportions D) densities

52. You should try to ______ your ambition and be more realistic.

A) reserve B) restrain C) retain D) replace

53. Nancy is only a sort of ______ of her husband’s opinion and has no ideas of her own.

A) sample B) reproduction C) shadow D) echo

54. Now that spring is here, you can ______ these fur coats till you need them again next winter.

A) put over B) put away C) put off D) put down

55. There is a _____ of impatience in the tone of his voice.

A) hint B) notion C) dot D) phrase

51.C) proportions 52.B) restrain 53.D) echo 54.B) put away 55.A) hint