The operation, which lasted for over four hours, proved to be very difficult because of the hard resin which covered the skin.
手术持续了4个多小时，非常难做，因为皮肤上覆盖着一层硬硬的树脂。
新概念英语第二册
Lesson 77 A successful operation
📚 句中词汇解析
从本句中提取的重要词汇
n. 操作，经营;手术;[数]运算;作用;
💡 oper 工作 + ation 表示行为、状态、过程 → n.操作；手术；运算
"a triple bypass operation"
接三通管的手术
近义：campaign, enterprise, errand, maneuver, maneuvering, manoeuvering
adj. 困难的;难做的;难解的;不易相处的;
💡 dif不+fic做+ult表名词→不好做→困难的
"The short story is a difficult art form to master."
短篇小说是一种很难掌握的艺术形式。
近义：rough, troublesome, complicated, arduous, intricate, labored
反义：uncomplicated, basic, cushy, doss, easy, facile
conj. 因为;
💡 cause, cuse 表原因,目的;司法程序,诉讼
"He was arrested because of his political affiliation."
他因所属政党的关系而被捕。
近义：since, whereas, for, forasmuchas
prep. （表示方向）越过;（部份或全部覆盖）在…上面;由于;（表示论及）关于;
adv. 结束;再;（倒）下;从一边至另一边;
adj. 过去的;外面的;在上的;上级的;
n. 额外;剩余;剩余（或多余）的量;剩余物;
int. [电信学]报文完，请回复！;
vt. 走过，跳过;[美国方言]从…恢复过来;
"The government did an about-turn over nuclear energy."
政府对核能的态度来了个180度的大转变。
近义：above, on, up, regarding, relating, respecting
反义：under, below, beneath
adj. 困难的;硬的;有力的;努力的;
adv. 努力地;猛力地;严重地;沉重地;
n. 英〉硬海滩，登陆处;
"She attributes her success to hard work and a little luck."
她认为她的成功来自勤劳和一点运气。
近义：strongly, rigidly, stiffly, resistant, resistive, steely
反义：malleable, mellow, mild, attenuated, softened, squashy