有几句话（被动语态）要变一般疑问句
把下面几句话变一般疑问句.我不太明白被动语态这点要怎么改.
1.It is called a clavichord .
这句我改的是：
Is it called a clavichord 问下这里的 called 用去ed吗?
2.It was made in Germany in 1681 .
3.Our clavichord is kept in the living room .
我想问下被动语态中的 done 在变成一般疑问句时用变成原形吗?
如果变,是在任何时态中都变?还是根据时态不同,而变?