81. I think it is important to _____ _____ _____ 　　　(平衡) study and a social life.

80. The body quickly ____ ____ (调节以适应)changes in temperature.

79. The farmer tried to _________their crops ________cold.(保护…不被冻坏)

78. He looked at his face ____(反射) in mirror.

77.If you don’t _____ your study______,(认真对待) you will fail in the coming examination.

76. The play ______ ______ ______ (改编自)a novel.