Question

It's sad ________ so many animals ________.

1. A.
   to hear about; have gone
2. B.
   to hear of; have been
3. C.
   hear about; have gone
4. D.
   hear of; has gone

Answer 1

A
点拨：“听说那么多的动物灭绝了真伤心。”it是形式主语，真正的主语是后面的动词不定式，故先排除C和D项。have gone既有“去了某地”也有“死了的，灭绝的”之意，而have been只有“去过或呆在某地”之意，所以B不正确。