51.

1. removal
2. catastrophe
3. accident
4. rise

52.

1. broke in
2. broke off
3. broke up
4. broke out

53.

1. intact
2. active
3. melting
4. changing

54.

1. was expected
2. had expected
3. would be expected
4. would have expected

55.

1. good as
2. well as
3. many as
4. much as

56.

1. dilating
2. disintegrating
3. declining
4. depreciating

57.

1. back through
2. back into
3. back forward
4. back from

58.

1. fewer than
2. less than
3. more than
4. higher than

59.

1. could
2. might
3. ought to
4. used to

60.

1. when
2. that
3. what
4. if

(Reference keys.)