Between 400 and 1000 giant pandas are ____ to live in mountains.

问题描述:

Between 400 and 1000 giant pandas are ____ to live in mountains.
A.thought B.believed C.seen D.said

选D,表示据说有400到1000的.
sth is said to be ...是据说什么什么.怎么怎么样了的意思