[填空题]
Sherlock Holmes is usia ,evfu 3t5i0jnfj -8eab5+jn0hls3gxa + y2 supio2e-g a 9.00-$cm$-focal-length lens as his magnifying glass. To obtain maximum magnification, where must the object be placed (assume a normal eye), and what will be the magnification?
$d_o$ = cm from the lens
M = $\times$
