51.

1. concussion
2. correction
3. recovery
4. sensitization

52.

1. underestimating
2. displaying
3. violating
4. deteriorating

53.

1. analogy
2. solicitation
3. explication
4. hypothesis

54.

1. devotedly
2. primarily
3. timely
4. merely

55.

1. distress
2. renewal
3. conflict
4. recurrence

56.

1. Imply
2. Admit
3. Deny
4. Argue

57.

1. concession
2. communication
3. confirmation
4. contraception

58.

1. disentanglement
2. disagreement
3. dissolution
4. disposition

59.

1. evidence
2. description
3. proof
4. record

60.

1. Consequently
2. Thus
3. Therefore
4. However

(Reference keys.)