是可数名词，意思是教科书，复数为textbooks，例如：
1.A part of the textbooks have arrived.一小部分教科书已经运到了。
2.It's not the world of textbooks.这不是教科书的世界。
3.Japan's education ministry ordered the change to encourage students to tear themselves away from textbooks.日本文部省下令实行这项改革，以鼓励学生从课本中走出来。
