9.85×99+98.5×0.1
=98.5×9.9+98.5×0.1
=98.5×(9.9+0.1)
=98.5×10
=985
俗话说“梨树砍三刀,果枝压弯腰”,在初夏梨树的“坐果”期,有经验的果农会给梨树的茎做半环状剥皮,这样做的目的是( )