—Why are you so happy today?—Because I to London with my parents tomorrow.
长江的发源地和注入的海洋分别是( )
如果把两条邻边中较短边与较长边的比值为5-12的矩形称作黄金矩形.现将长度为20cm的铁丝折成一个黄金矩形,这个黄金矩形较短的边长是 ____ cm.