Here are the underlined parts that need correction for each sentence:

56. His father was **so** poor **to** send him to school.
**Correction:** "so" should be replaced with "too."
Revised: His father was **too** poor to send him to school.

57. She is **such** good at mathematics that everyone admires her.
**Correction:** "such" should be replaced with "so."
Revised: She is **so** good at mathematics that everyone admires her.

58. George is **not enough** intelligent to pass this mathematics class.
**Correction:** "not enough" should be replaced with "not very."
Revised: George is **not very** intelligent to pass this mathematics class.

59. The novel was **such** interesting that I had read it all night.
**Correction:** "such" should be replaced with "so."
Revised: The novel was **so** interesting that I had read it all night.

60. He was **tired that** he couldn't continue his work.
**Correction:** "tired that" should be replaced with "so tired that."
Revised: He was **so tired that** he couldn't continue his work.

61. His TOEFL score was **enough high** to be accepted.
**Correction:** "enough high" should be replaced with "high enough."
Revised: His TOEFL score was **high enough** to be accepted.

62. It was **so an** exciting novel that I do not want to stop reading it.
**Correction:** "so an" should be replaced with "such an."
Revised: It was **such an** exciting novel that I do not want to stop reading it.

63. The woman was **too old that** she could not run.
**Correction:** "too old that" should be replaced with "too old to."
Revised: The woman was **too old to** run.

64. These televisions are all **too expensive for we** to buy at this time.
**Correction:** "we" should be replaced with "us."
Revised: These televisions are all **too expensive for us** to buy at this time.

65. My brother is **too young not to** do volunteer work.
**Correction:** "too young not to" should be replaced with "too young to."
Revised: My brother is **too young to** do volunteer work.

66. These televisions were **so expensive for us** to buy at that time.
**Correction:** "so expensive for us" can remain as is but often can be adjusted to "too expensive."
Revised: These televisions were **too expensive for us** to buy at that time.

67. That is **such an interested** story that everybody would like to read it.
**Correction:** "interested" should be replaced with "interesting."
Revised: That is **such an interesting** story that everybody would like to read it.

68. The road is **very slippery for us** to drive fast.
**Correction:** "for us" can remain as is but often can be adjusted to "for us to."
Revised: The road is **very slippery for us to** drive fast.

69. He had **so a** difficult exercise that he couldn't do it.
**Correction:** "so a" should be replaced with "such a."
Revised: He had **such a** difficult exercise that he couldn't do it.

70. John had **so interesting and creative** plans that everyone wanted to work with him.
**Correction:** "so interesting and creative" should be replaced with "such interesting and creative."
Revised: John had **such interesting and creative** plans that everyone wanted to work with him.