Suddenly they came to a waterfall which dropped into an underground lake at the bottom of the cave.
突然，他們來到一道瀑布前，那瀑布奔瀉而下，注入洞底一處地下湖里。
新概念英語第三冊
Lesson 42 Modern cavemen
?? 句中詞匯解析
從本句中提取的重要詞匯
adv. 意外地，忽然地;奄;勃;霍然;
?? sudden突然的 + ly ...地 → adv.突然地
"Suddenly he found himself awake and fully alert."
突然他發覺自己醒了過來，而且高度警覺。
近義：impromptu, inadvertently, abruptly, offhand, overnight, sharply
反義：progressively, slowly, sparingly, stingily, inchmeal, consecutively
n. 瀑布;瀑布似的東西;<美俚>（披垂的）波型長發;
?? water水+fall落下 → 瀑布
"A cloud of fine spray came up from the waterfall."
飛瀑濺起一片水霧。
近義：cascade, cataract, chute, fall
adj. 地下的;秘密的;先鋒派的;隱蔽的;
?? under在…下+ground地→地下的
"a secret underground passage"
地下秘密通道
近義：subsurface, subterranean, subterraneous, buried, backdoor, secret
反義：jural, lawful, legit, legitimate, licit, original
n. 洞穴;〈方〉地窖;
vt.& vi. （使）塌陷，倒塌;暗中破壞;
vi. 屈服;
?? cav洞+e → 山洞，洞穴，窯洞
"a dark dank cave"
陰暗潮濕的洞穴
近義：dig, excavate, cavern, crypt, den, dugout
n. 湖;深紅色顏料;胭脂紅;[化]色淀;
vt.&vi. 血球溶解;使（血液）發生血球溶解;
"Fish are abundant in the lake."
湖里魚很多。
近義：lagoon, loch, lacustrine