The connected components form a three-tiered system that looks like a triple-decker sandwich.
这些连接起来的三层式的系统，看起来像个三层的三明治。
2
That morning, three bombers detonated themselves in three of London'sUnderground trains, before a fourth explosion occurred on adouble-decker bus in Tavistock Square an hour later.
America's national Marine mammals laboratory scientists to measure the length of the longest for 29.9 m, whales and probably Boeing 737 or three double-decker buses.