Here are the correct answers for the questions:

80. B. has been discovered
81. C. have finished - arrived
82. C. punishing
83. D. has typed
84. A. made
85. A. done
86. B. delivered
87. B. is making
88. C. didn’t used
89. B. were born
90. A. not to object to being
91. B. have been helping
92. B. to be sold
93. C. follow
94. A. bit
95. C. was cleaned
96. B. suspects/ has been burying
97. B. is believed to have been discovered
98. C. need to type
99. C. made
100. B. is being installed
101. C. is being repaired
102. B. was written by
103. B. are broken down and converted
104. C. is easily absorbed
105. C. have been taught
106. B. be used

Feel free to ask if you need further explanations!