解释一下这个句子的语法 成分when john walked around the museum to see if everything was all right.我把这个句子完整的写出来 请分析一下句子结构（就是主语谓语宾语等各是什么）one day,when john walked around the museum to see if everything was all right,he found a painting lying on the floor.只分析这个句子就可以了

解释一下这个句子的语法 成分
when john walked around the museum to see if everything was all right.
我把这个句子完整的写出来 请分析一下句子结构（就是主语谓语宾语等各是什么）
one day,when john walked around the museum to see if everything was all right,he found a painting lying on the floor.
只分析这个句子就可以了