单选题 We spent the day ______ through forests and over mountains.

【正确答案】 C
【答案解析】[解析] trek步行,尤指长途步行越过山区;drudge(at,over)做苦工;dribbling(燃料或油从系统内)漏泄;thump(at,on)心脏卜卜地跳。正确答案为C项。