[填空题]
A woman can see clearly with h 6as vm65gagj7er right eye only when objects are9a grgbnp:o,f:gurre5 22c4b; 2 wqsj between 45 $cm$ and 155 $cm$ away. Prescription bifocals should have what powers so that she can see distant objects clearly (upper part) and be able to read a book 25 $cm$ away (lower part) with her right eye? Assume that the glasses will be 2.0 $cm$ from the eye.
$P_1$ = D(upper part)
$P_2$ = D(lower part)
