62. The United States [is composed of ]fifty states, [two of those] are
            A                                      B
[separated from] [the others] by  land or water.
       C                      D       
答案：B。应改为：two of which。非限定性定语从句，which在从句中指fifty states。

63. The news [coming from] [different parts] of the world [are] often
          A             B               C    
[extremely discouraging] these days.  
               D 
答案：C。应改为is。当以news （新闻）, means（方法），works （工厂）等一般被认为是形式是复数，意思是单数的词，做主语时谓语动词一般用单数形式。Every means has been tried.每一种方式都试过了。Here is the news.现在报告新闻。

64. We [had lived] in this house for three years [while] my father
                  A                     B
decided [to have] us [move] to a new neighborhood.
                 C               D
答：B。应改为before.符合逻辑关系。意思：“在我父亲决定搬家之前,我们已经在这里住了两年了。” 

65. I [don’t think] I can [understand] this book, the subject [it] deals
       A               B                     C
[with] is not familiar with me. 
   D 
答案：D：应改为to。be familiar to：熟悉…，后面常跟人做宾语。如：His name was familiar to many people.许多人熟悉他的名字。be familiar with:熟悉…后面常跟物做宾语。如：He is familiar with English.他通晓英语。

66. Nancy had [a great deal of] trouble [to Concentrate on] her work
                 A            B     
[because of] the noise [in] the next room. 
         C                      D