74. The students couldn't understand the theory,so the teacher had to explain it _____________.

73. He is addicted to playing computer games, so he can’t 　_______________his lessons in class.　　

72. Don’t waste time . Our head teacher won’t ____________ our doing such a thing.

71. Do you believe that the robot will _________________humans completely in the future?.　

70. The mother_______________and began to cry when she heard that her son was lost.

69.The colour of the dress will fade when _______________the sunlight for long.

注：此题答案要写在答题卷上。

根据所提供的语境，从方框中选择正确短语填空，使句子完整。(其中有两个多余词)

68.It’s a suggestion ______________by my boss.