So he keeps on studying after his English classes in order to prepare for life in America.
所以他在英语课下课后还继续学习,为以后在美国生活做准备。
do in fact run out of energy in accordance with the second law of thermodynamics (whether the whole universe does so is a moot point at present).
也都会消耗完其能量(整个宇宙是否如此,目前尚有争论)。