关于to be 的用法

goodbaby102

下面是关于to be用法的两个题目，为什么一个可以用，一个不可以用啊，有人可以帮忙解释一下吗？

1，The World Wildlife Fund has declared that global warming, a phenomenon most scientists agree to be caused by human beings in burning fossil fuels, will create havoc among migratory birds by altering the environment in ways harmful to their habitats.

• Aa phenomenon most scientists agree to be caused by human beings in burning fossil fuels,
• Ba phenomenon most scientists agree that is caused by fossil fuels burned by human beings,
• Ca phenomenon that most scientists agree is caused by human beings' burning of fossil fuels,
• Dwhich most scientists agree on as a phenomenon caused by human beings who burn fossil fuels,
• Ewhich most scientists agree to be a phenomenon caused by fossil fuels burned by human beings,
  这题的正确答案是C，否定了A中agree to be的用法，请看下一题
  

2，
According to recent studies comparing the nutritional value of meat from wild animals and meat from domesticated animals, wild animals have less total fat than do livestock fed on grain and more of a kind of fat they think is good for cardiac health.

• Awild animals have less total fat than do livestock fed on grain and more of a kind of fat they think is
• Bwild animals have less total fat than livestock fed on grain and more of a kind of fat thought to be
• Cwild animals have less total fat than that of livestock fed on grain and have more fat of a kind thought to be
• Dtotal fat of wild animals is less than livestock fed on grain and they have more fat of a kind thought to be
• Etotal fat is less in wild animals than that of livestock fed on grain and more of their fat is of a kind they think is
  这题正确答案是B，肯定了thought to be的用法
  

谁可以分析一下为什么一个可以用thought to be 而一个不可以用agree to be呢？ 谢谢

kiwifoodtown

简单的说一下，LZ可能理解错了，1句中LZ 把它看成是agree to be是不对的，首先agree是作为most scientists的谓语，而be caused 是针对a phenomenon，两者不能简单串联为agree to be caused. 这样就会造成句子的行为对象混乱。所以在C选项中，就加以区分，a phenomenon 用that is caused by。。。这个定语加以修饰，而most scientists agree 是作为插入语。这个句子和agree to be没有关系。

而2句，thought to be完全是过去分词作定语来修饰a kind of fat。所以，它是要和句子逻辑意思相符合，它和上一句无可比性。