All the afternoon he worked in his study with the door ______.
A. to lock B. locking C. lock D. locked
出自:统招专升本-----英语

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