—Look at these tracks. It _____ be a wolf.—It needn.t be. It _____ be a fox.( )
·must; could
·may; might
·need; must
·could; need
出自:佳木斯大学语言治疗学

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