76. The number of people invited was fifty, but a number of them was absent for different reasons.
77. The first two of the five questions on the test paper were very difficult, but the rest was easy.
78. It is no use cry over the spilt milk.
79. I had great difficulty find out the answer to the question.
80. Learning new words are very useful to me.
81. She is the only one of the students who have been invited to the party.
82. This book is worthy being read.
83. The windows which faces south are all broken.
84. The letter that I was looking forward to coming at last.
85. Who was the last one leave the room last night?