我查了下爱词霸, be known
as
以...知名; 被认为是; 称为 be known to
为...所知
但是新东方蓝皮书上有一题是这样的:
Until a few centuries ago, any large bones discovered in the
fields or caves of Europe, now known tobe large prehistoric animals, were
usually assumed to be the remains of giants and were
often.........
答案是 C bones now known to be those of large prehistoric
animals, were usually assumed to be
为什么这里用known to be 呢? known as 和 known to be
分别是什么意思呢... | 
