1.I am not going to turn down an invitation to go to New Yor

1.I am not going to turn down an invitation to go to New York!
为什么用turn down?
2.set out和set about用法上有什么区别?
3.How did the car accident______.
空中填occur还是happen,或者二者都行?
4.Where did you_____your knowledge of Chinese history?
空中填acquire还是obtain,或者二者都行?

1.第一句话的意思是：我不打算拒绝去纽约的邀请喔.
turn down 是比较委婉地拒绝的意思,在日常生活当中比较常用.
2.意思上是比较相近的：开始,着手干某事；
但切记：set out +to +V.(动词原型)
set about +V.ing (动词的现在分词形式),这是语法上的规定,很容易理解的：
你就这样子理解着记就行了!：about 是介词,所以后面只能接动词的现在分词形式.
acquire 和obtain无论是在语义上还是在用法上都是存在着写区别的：
occur vi.发生,出现
happen强调偶然性
eg.There happen to be no money with me.
It so happens that...
而 occur是一般用词,可指某事情偶然发生或者按照计划进行,在表示具体失去的名词作主语的时候,可与happen换用,但比较正式,跟to短语时,表示“想到”,而不是“发生”
eg.I’m very sorry for all happened to you.
An idea occurs to me that going to Switzerland for traveling will be marvelous!
所以,第三题应该选择happen,因为事故的发生是具有不确定性的,即在这里强调偶然性.
4.这两个词词义上真没什么过多区别
牛津和剑桥都是两个互为解释的~
如果硬要区别,acquire有种慢慢获得的意思
而obtain则有种通过努力的意思,
但也不绝对,主要还是搭配问题,注意几点见下：
用法和搭配上注意几点
1.obtain搭配 advice/information/permission
eg.Have you obtained permission into the hall?
2.obtain 经常用manage to obtain sth,而acquire不这么用
eg.He finally managed to obtain what he wanted.
3.acquire搭配 a knowledge/reputation/taste(habit)
eg.He acquired a good knowledge of English during his stay in England.
He has acquired a reputation for dishonesty.
I have acquired a taste for(=like) olives these days.
(这个意思有个引申词组,an acquired taste 开始觉得不好,但慢慢觉得好了
eg.Maybe you will not get interested in Jay's songs at first,but when you listen quietly,you will find an acquired taste in it.）
其他用法两个基本可以通用
所以,第四题应该选择acquire,因为在这里强调的是一个慢慢的获得知识的过程.
要跟句具体给出的语境作出适当的选择,同时也要注意某些特定词语的固定搭配,这对你以后的学习都有非常大的益处!