说白了: to speak frankly...
预习: to prepare a lesson...
明亮: bright, shining, glittering, to become clear...
开关: power switch, gas valve, to open the city (or frontier) gate, to open and close, to switch on and off...
墓地: cemetery, graveyard...
略微: a little bit, slightly...
散步: to take a walk, to go for a walk...
洞: cave, hole, zero (unambiguous spoken form when spelling out numbers)...
恩怨: gratitude and grudges, resentment, grudges, grievances...
玩耍: to play (as children do), to amuse oneself...
