倍数总结：once --- 一倍 ; twice --- 两倍；三倍及三倍以上 --- 基数词 + times
1. 倍数 + as + 形容词(原级) + as ...
例如：My school is twice as big as yours.
2. 倍数 + 形容词(比较级) + than ...
例如：This building is four times higher than that.
3. 倍数 + the size / length/ height / width... + of ...
例如：This building is four times the height of that.