[填空题]
A physicist lost in the mountabe,;;uhu7 u avins tries to make a telesc(bmy*psc8s s *gosv. cn:erg b04x8k( ope using the lenses from his read*8cp*gmvgsb4b8ecys r (nk0xo. s( s :ing glasses. They have powers of $+2.0-D$ and $+4.0-D$, respectively.
(a) What maximum magnification telescope is possible? $M$ = $\times$
(b) Which lens should be used as the eyepiece? D
