在前沿
相近词汇：
ahead three again ahead 再进三
create curve-curve 创建曲线
curve divide curve 用曲线分割曲线
curve learning practice curve 实践曲线
curve of error; error curve 错误曲线
curve of forgetting; forgetting curve 遗忘曲线
curve of improvement; improvement curve 进步曲线
curve of learning; learning curve 学习曲线
curve of memory; memory curve 记忆曲线
curve of practice; practice curve 练习曲线
curve of pursuit curve 追踪曲线