英语一种句型讲解一下he lives in a village ____there are a lot of trees

1.B
定语从句中,关系副词where = 介词 + 关系代词 = 介词 + 先行词.
此题where = in/at which = in/at the village
而定语从句为：where there are a lot of trees = in/at which there are a lot of trees = in/at the village there are a lot of trees
调整句序即为：there are a lot of trees in/at the village
2.C
一般疑问句含有定语从句时,最好把它还原成陈述句.
此题还原成：This factory is ____ you visited last week.
很明显,如果用which/that/where直接引导一个定语从句的话,则主句连表语(先行词)都没有.
所以必须选入the one = the factore做先行词,主句才完整.
而关系代词which/that相当于先行词the one/factory,在定语从句中充当动词visited的宾语,所以which/that可以省略.
3.关系代词相当于先行词(即被定语从句所修饰的代词/名词短语),在定语从句中一般做主语/表语/宾语等.第2题的关系代词就是直接做visit的宾语；
而关系副词=介词+关系代词=介词+先行词,在定语从句中充当状语.第1题的where就在定语从句中充当地点状语.

B和A

这是定语从句。
第一句，in a village是后面一句的地点状语，所以用where
第二句，factory 是后面一句的visite的宾语，而且是物不是人，所以用which，如果是人而不是物，则用whom
参考：
http://baike.baidu.com/view/56536.htm#1

BA
定语从句