51.

1. in the way
2. out of the way
3. on the way
4. all the way

52.

1. amputate
2. ameliorate
3. aggravate
4. anticipate

53.

1. a talented
2. a special
3. a professional
4. an amateur

54.

1. instinct
2. proposal
3. hypothesis
4. institute

55.

1. stand up for
2. stand up to
3. stand in for
4. stand in with

56.

1. adjust
2. adjusted
3. adjusting
4. adjustable

57.

1. reduce
2. regulate
3. alleviate
4. increase

58.

1. overcome
2. remove
3. stimulate
4. emulate

59.

1. strain
2. tension
3. conflicts
4. arguments

60.

1. solved
2. evolved
3. revolved
4. involved

(Reference keys.)