假设下图中琼脂块含生长素的量和胚芽鞘尖端所产生的生长素量相同,则一段时间后对a、b、c、d四个空白琼脂块中所含生长素量的分析正确的是( )
A:c>a=b>d
B:a=c>b=d
C:c>a>b>d
D:a>c>d>
____ ____ ____ that the earthquake led to many people ____ ____ alive.