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。