问一下这句英语当中从句部分（即空格后边）缺的是什么成分?（主语or宾语?）When changing lanes,a driver should use his signal to let other drivers know _______ lane he is entering.
问题描述：
问一下这句英语当中从句部分（即空格后边）缺的是什么成分?（主语or宾语?）
When changing lanes,a driver should use his signal to let other drivers know _______ lane he is entering.
答
what
是作为know的宾语
答
which,缺少宾语。
答
宾语,know之前所有句子可忽略,等价于一个know从句
陈述语句为he is entering lane,对其提问,what lane is he entering,在从句中改变语序,即得题干内容
答
which