The weather in Beijing is better than ----in Moacow.A itB on

答案：C
that 指代前面的天气,是同名异物.it／one ／that三者均可用作代词,指代前面提到的名词.一般说来,it指代同名同物; one与that则指代同名异物.
I have lost my umbrella; I'm looking for it.（该句中it就是指前面的my umbrella）
I have lost my umbrella; I think I must buy one.（one在该句中表泛指,因为my umbrella已经丢了）
The umbrella you bought is cheaper than that I bought.（替代词that在该句中特指“the umbrella I bought”,以区别“the umbrella you bought”）
更上一层楼!(⊙o⊙)

C

C. 北京的天气比澳门的天气好。that 是特指一类事物，这里特指澳门的天气。

A