It is a challenging task to ____ those disappointed students.
A.turn on B. turn in C. turn down D. turn off
出自:英语(专升本)

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