题干
I can't play with Alan, I have a lot of things to do.
A： so
B：because
C：but
D： and
答案(点此获取答案解析）
B
I can't play with Alan, I have a lot of things to do.
A： so
B：because
C：but
D： and
纸，对折一分为二裁开成为 
纸，再一分为二成为 
纸，…，它们都是相似的矩形．求这种纸的长与宽的比值（精确到千分位）．