51.

1. already
2. still
3. only
4. once

52.

1. took
2. threw
3. sent
4. put

53.

1. impossible
2. difficult
3. stressful
4. hopeless

54.

1. decisions
2. experience
3. ambitions
4. beliefs

55.

1. suggests
2. promises
3. seems
4. requires

56.

1. something
2. anything
3. nothing
4. everything

57.

1. Surprisingly
2. Immediately
3. Naturally
4. Certainly

58.

1. touched
2. astonished
3. attracted
4. warned

59.

1. quiet
2. calm
3. relaxed
4. happy

60.

1. doubt
2. wonder
3. know
4. guess

(Reference keys.)