题目

There are some very good things about open education. This way of teaching allows the students to grow as people, and to develop their own interests in many subjects. Open education allows students to be responsible for their own education, as they are responsible for what they do in life. Some students do badly in a traditional classroom. The open classroom may allow them to enjoy learning. Some students will be happier in an open education school. They will not have to worry about grades or rules. For students who worry about these things a lot, it is a good idea to be in an open classroom.  电阻R1=15Ω、R2=10Ω，R1、R2串联后的总电阻是      Ω；并联后的总电阻是      Ω。