Is this museum ________ they visited some ancient weapons yesterday?

B．where 是对的.
这是定语从句,先行词museum,定语从句they visited some ancient weapons yesterday 成分完整,而引导词要在定语从句中做地点状语,故引导词选where或in which.
逻辑上,Is this museum________ they visited yesterday?这个又如何理解呢？不是说没先行词吗这题有点不同。没错，定语从句缺少先行词，所以填进去的单词，必须具备先行词的功能，只有the one或者one适合，但这里是特指，只能选the one。定语从句they visited yesterday缺少宾语，visited是及物动词，是必须带宾语的。所以不能再用where了，只能用that或者不填。