You can have an interactive learning experience, such as playing videos, examining geometrical problems in 3D, listening to music and commentary, making notes and marking passages electronically.

选择一项:
对
错
出自:国家开放大学-人文英语3

完成拼图验证

按住下方滑块,将拼图拖到缺口处后松开。

拼图背景,将小拼图拖到缺口处
向右拖动滑块