according to a BBC investigation , you could stack a quarter of a million 2x2 bricks on top of each other before the bottom one collapsed . 9
根据英国广播公司（BBC）的研究结果，如果你把2×2的乐高积木一块一块往上叠，需要叠25万块积木才能让最下面那块积木崩溃。9
2x2