Since information and knowledge in every field is doubling every 2-3 years, this means that your knowledge has to double every 2-3 years as well.
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