The future can be difficult. There are many famous predictions 1 never came true.Before 1929, there was no sound in movies. The head of one of the2movie companies in the United States predicted that no one would want to see actors 3. Of couse,he was wrong! In 1979,the head of the largest computer company in the United States said,“No one will want to have a computer in his or her home.” He thought that computer would never 4by most people.

某学校把学生的期末测试、实践能力两项成绩分别按60%，40%的比例计入学期总成绩，小明实践能力的得分是80分，期末测试的得分是90分，则小明的学期总成绩是（　　）

研究动物行为的方法主要有（　　）