(1) Can you understand French? (2) Do you understand the instructions? (3) She didn't understand the form she was signing.
understand [ˌʌndəˈstænd] 📢 UK📢 US
vt.& vi.懂，理解； vt.了解；默认；听说；领会；
vt.松开，解开；取消，废除；毁灭；扰乱； vi.撤销；
n.剪刀；两腿前后错跃； v.剪开( scissor的第三人称单数)；作剪式移动（尤指腿）；
adj.老式的，过时的；老派的，守旧的；村女蛾眉；陈旧；
(1) a military/police/nurse's uniform (2) soldiers in uniform (3) The hat is part of the school uniform .
uniform [ˈju:nɪfɔ:m] 📢 UK📢 US
n.报考者；申请求职者；攻读学位者；最后命运或结局如何已显然可见者；
众所周知的；出名的；
n.车库；汽车修理站；飞机库； vt.把…送入车库；把（汽车）开进车库；
n.制服；军服；通讯中用以代表字母 u 的词； adj.（形状，性质等）一样的；规格一致的；始终如一的； v.使规格一律；使均一；使穿制服；
(1) The desire to be a mother may creep up on you unexpectedly. (2) Miserable, and unexpectedly lonely, she went in search of Jean-Paul. (3) She panics when people pop in unexpectedly, rushing round plumping cushions.
(1) They're both uncertain about what to do. (2) I'm still uncertain of my feelings for him. (3) Our future looks uncertain.
uncertain [ʌnˈsɜ:tn] 📢 UK📢 US
n.耐心，耐性；忍耐；单人纸牌游戏；
n.[化]元素；要素；原理；[电]电阻丝；
adj.不确定的；不稳定的；不明确的；无常的；
觉得要呕吐；作呕；
(1) I put up my umbrella. (2) colourful beach umbrellas (3) Many previously separate groups are now operating under the umbrella of a single authority.
umbrella [ʌmˈbrelə] 📢 UK📢 US
n.没有人；
n.雨伞；〈比喻〉保护物；[军]空中掩护幕；总括；
n.电梯；升降机（美）；谷仓；
n.滥用；恶习；侮辱；恶言； vt.滥用；虐待；辱骂；
(1) underwater creatures (2) an underwater camera (3) Take a deep breath and see how long you can stay underwater.
(1) The committee has little or no understanding of the problem. (2) The existence of God is beyond human understanding (= humans cannot know whether God exists or not) . (3) We finally came to an understanding about what hours we would work.
(1) I must write and thank Mary for the present. (2) There's no need to thank me─I enjoyed doing it. (3) In his speech, he thanked everyone for all their hard work.
(1) He lay there, unable to move. (2) I tried to contact him but was unable to. (3) The military may feel unable to hand over power to a civilian President next year...
unable [ʌnˈeɪbl] 📢 UK📢 US
（要）…而不…，与其…倒不如…；instead of sb/sth 而不是；
n.水平，水准；水平线，水平面；水平仪；[物]电平； adj.水平的；同高度的；平均的；平稳的； vt.使同等；对准；弄平； vi.拉平；（用枪等）瞄准（与 at 连用）；变得平坦；将（话、批评等）对准目标； vi.瞄准；拉平；变得平坦；
adj.不能的，不会的；无能力的，不熟练的；不能胜任的；〈罕，诗〉弱，无力的；
adj.妒忌的，妒羡的；猜疑的，留意堤防的；爱惜的，戒备的；精心守护的；
(1) Such behaviour is totally unacceptable in a civilized society. (2) Noise from the factory has reached an unacceptable level. (3) unacceptably high levels of unemployment
(1) There was a lot of unhappiness in my adolescence. (2) His laugh-a-minute image is just a front to hide his deep unhappiness. (3) He had sensed his mother's unhappiness.
(1) unfortunately, I won't be able to attend the meeting. (2) I can't make it, unfortunately. (3) unfortunately for him, the police had been informed and were waiting outside.
(1) a technical/legal/scientific, etc. term (2) a term of abuse (3) ‘Register ’ is the term commonly used to describe different levels of formality in language.
(1) The coin rolled underneath the piano. (2) This jacket's too big, even with a sweater underneath. (3) underneath her cool exterior she was really very frightened.
(1) He unfairly blamed Frances for the failure. (2) He had unfairly presented a caricature of my views. (3) Workers who have been unfairly dismissed may claim compensation.
(1) an unfriendly atmosphere (2) There's no need to be so unfriendly towards them. (3) the use of environmentally unfriendly products (= that harm the environment)
(1) Have you looked under the bed? (2) She placed the ladder under (= just lower than) the window. (3) The dog squeezed under the gate and ran into the road.