在下列现象中,能量是怎样转化的?
(1)用锯锯木头,过一会锯条变热了;______________________
(2)木材燃烧,发光发热;_________________________________
(3)植物进行光合作用;_________________________________
(4)电动机通电后转动起来;_________________________________
(5)核电站发电;_________________________________
(6)蓄电池放电;_________________________________
(7)对蓄电池充电。_________________________________