71. The wooden horse was too heavy for them to take with them.

　　72. Their job is to tell jokes and make people laugh.

　　73. Then Joyce took charge of the meeting.

　　74. These photos belonged to a student’s mother.

　　75. They agree to talk over the title for the newspaper with us.

　　76. They are not wealthy, but they are happy and healthy.

　　77. They denied stealing the vase, but I noticed Jill wearing a black pearl necklace.

　　78. We agreed to conclude the meeting.

　　79. We are polluting it with chemicals-- in the form of gases.

　　80. We arranged to have the next meeting in one week's time.