deal：v.a.发牌；to give cards to each player in a game of cards
b.买卖,经营；to buy and sell a particular product
unless:conj.a.除非；used to say that sth can only happen or be true in a particular situation
b.若非,如果不；used to give the only situation which sth will not happen or be true
unfair:adj.a.不公正的,不公平的；not right or fair according to a set of rules or principles
b.待人不公平的；not treating people equally
affect:v.a.影响to produce a change in sth
b.入侵,感染；to attack sb or a part of a person;make sb sick
solve:v.a.解决;处理；to find a way of dealing with a problem or difficult situation
b.破解；to find the correct answer or explanation for sth
challenge:n.a.挑战,艰巨任务；a new or difficult task that tests sb's ability or skill
b.挑战书,（比赛等的）邀请an invitaion or suggestion to sb that they should enter a competition,fight,etc
regard:v.a.把...视为；to think about sth or sb in a purticular way
b.注视,凝视；to look at sb or sht ,especially in a purticular way
smart:adj.a.聪明的,机敏的；intelligent ,
b.智能的；controlled by a computer ,so it appears to act in an intelligent way
duty:n.a.责任,义务；sth that you feel you have to do it because it is your moral and legal responsibility
b.值日,值班；the work that is your job
instead:adv.a.代替,作为...的替换；in the place of sth or sb
b.
上面的都是我自己查找资料总结出来的,instead只有一个意思；根据我多年来学习英语的经验,要学好单词,最有用的是例句,把例句和汉语背好了,用法也学会了,不容易忘记