Living in the Central American desert has its problems,()obtaining water is not the least.A.of which B.for what C.as D.whose求具体解释为什么,

Living in the Central American desert has its problems,()obtaining water is not the least.A.of which B.for what C.as D.whose求具体解释为什么,
Living in the Central American desert has its problems,()obtaining water is not the least.
A.of which B.for what C.as D.whose求具体解释为什么,

Living in the Central American desert has its problems,()obtaining water is not the least.A.of which B.for what C.as D.whose求具体解释为什么,
选A 后面的句子其实是个省略句,完整的句子是这样的
Living in the Central American desert has its problems,(of all its problems)obtaining water is not the least.
problem作为了先行词,而且是物,所以用which来代替了,前面的of不可省略
不懂再问