be short of 就是“……的缩写”
如：BB is short of Blackboard
还有另一种形式be short for
如：Blackboard is short for BB
2 有“缺少……”之意
We're short of cash.
我们的资金不足
1.be short of 缺乏（反义词组：be rich in）she is short of food.
2.的缩写Phone is short of telephone.
be known as 意思是:作为.而出名,它的后面可以跟表示某种职业或某物的名词.例如：
Lu Xun is known as a writer.
鲁迅是作为作家而出名.
Zhou Jielun is known as a rap singer.
周杰伦是作为一个rap歌手而出名.