问题补充：
Living in the central Australian desert has its problems, getting water is not the least.
A. as
B. of which
C. whose
D. for what
答案：
A. as
(答案→)B. of which
C. whose
D. for what
解析：考查定语从句，介词+which引导定语从句，of这里表示从属关系，which指its problems，句意是：住在澳大利亚中部有它的问题，其中取水不是最小的问题。选B。
考点; 考查定语从句
