1.ongoing a.进行中的,不间断的(continuing)
例:They highlight her ongoing efforts to reform sanitary conditions after the war.
2.onset n.发作.(突然)开始(beginning start)
分拆记忆:on+set(放)--放在…上--发作,开始
例:I knew my sneezing was the onset of a major cold.,,at the very onset刚一开始
3.opaque a.不透明的(not transparent);难懂的(obscure)
词根记忆:opa(不透明)+que--不透明的
例:The room was dark because all of the windows were opaque.// I couldn't understand my professor's opaque lecture.
4.operagoer n.经常看歌剧的人(a person who frequently goes to operas)
分拆记忆:opera(歌剧)+goer(帝去的人)--经常看歌剧的人
例:Just as reading Samuel Pepys's diary gives a student a sense of the seventeenth century-of its texture and psyche-so listening to Jane Freed's guileless child narrator takes the operagoer inside turn-of-the-century Vienna.
5.optical a.眼的,视觉的(visual);光学的(of or relating to optics)
词根记忆:optic(眼的)+al--眼的,视觉的
例:optical illusion //an optical instrument光学仪器
6.optimal a.最佳的(best);n.最大限度(top)
词根记忆:optim(最好)+al--最佳的
例:This is the optima/time for harvesting apples.
7.optimism n.乐观,乐观主义(a tendency to expect the best possible outcome or dwell on the most hopeful aspects of a situation)
词根记忆:optim(最好)+ism--认为自己是最好的--乐观,乐观主义
注意:pessimism(n.悲观,悲观主义)
例:Increasing commercial activity would create a mood of optimism about national prosperity.
派生词:optimistic(a.乐观主义的)i optimistically( ad.乐观地)
8.optimum a.最好的,最有利的(most favorable or advantageous)
词根记忆:optim(最好)+um--最好的
例:I raised my exotic plants under optimum conditions.