Oil rigs have to be repaired frequently and divers,who often have to work in darkness a hundred feet under water,
钻井平台需要经常修理，潜水员常常要在水面100英尺以下摸黑工作，
新概念英语第二册
Lesson 90 What's for supper
📚 句中词汇解析
从本句中提取的重要词汇
adv. 频繁地，屡次地;往往;动;动辄;
💡 frequent经常的+ly...地 → 经常地，频繁地
"The group have frequently used bully-boy tactics."
那个团伙常常耍流氓。
近义：oft, often, oftentimes, periodically, regularly, repeatedly
反义：occasionally, rarely, seldom, sporadically
n. 黑暗;阴郁;模糊;无知;
💡 dark黑暗的+ness表名词 →黑暗
"They left under the cloak of darkness."
他们在黑暗的掩护下离开了。
近义：murk, murkiness, obscurity, tenebrosity, blackness, dark
反义：lightness, limpidity, lucidity, pellucidity, splendor, transparence
a. 各种不同的\\npron. 若干个, 好几个
近义：manifold, many, several, some, sundry, various
adv. 常常;经常;时常;再三;
💡 十(ten)有八九的(of)， 经常的
"Sleep has often been thought of as being in some way analogous to death."
人们常常认为睡眠在某种意义上来说类似死亡。
近义：manyfold, oft, oftentimes, repeatedly, usually, offtimes
反义：infrequently, occasionally, seldom, sometimes
vt.& vi. 使工作;使运作;操作;使产生效果;
n. 工作，操作;著作;工厂;行为，事业;
vt. 使工作;操作;经营;使缓慢前进;
"to be absent from work"
缺勤
近义：labor, labour, function, process, tool, malleate
反义：idle, laze, loaf, loiter, ramble, roam