求助：蓝皮part1_9

Astronomers at the PO have discovered a distant supernova explosion, one that they believe is type previously unknown to science.

A:that they believe is

B:that they believe it to be

C:they believe that it is of

D:they believe that is

E:they believe to be of

为什么？请分析一下句子结构。

请MM贴全题目

这里的考点是they believe是不是插入成分 如果按照A 那么they believe就是个插入成分 拿掉以后就是 one that is type perviously unknown to science.怎么能对呢？

那么E就把they believe变成实实在在的成分 that是关系代词代belive的宾语one

they believe (one) to be of type

Longman上也有of type这种固定用法1
[countable] one member of a group of people or things that have similar features or qualities
of this/that/each etc type
I've already seen a few movies of this type.

MM给你一道类似的题目这个题和你问的题是一个出题思路 都是看考生能不能分辨出插入语和实实在在的成分 那么区别就在于 有的动词两种功能都有 像believe 你说they belive插入语也行 说they belive sth. to be sth.也行 但是下面这个题中考的claim就不一样了

The electronics company has unveiled what it claims to be the world's smallest network digital camcorder, the length of which is that of a handheld computer, and it weighs less than 11 ounces.

(A) to be the world's smallest network digital camcorder, the length of which is that of a handheld computer, and it weighs

  (B) to be the smallest network digital camcorder in the world, which is as long as a handheld computer, weighing

  (C) is the smallest network digital camcorder in the world, which is as long as a handheld computer, and it weighs

 (D) is the world's smallest network digital camcorder, which is as long as a handheld computer and weighs

(E) is the world's smallest network digital camcorder, the length of which is that of a handheld compute

答案C 主要是没有claim sth. to be sth.的用法 不可以说it claims what to be

Longman中有▶TRUTH◀
[transitive]to state that something is true, even though it has not been proved
claim (that)
The company claims that their product 'makes you thin without dieting'.
claim to do/be something
No responsible therapist will claim to cure your insomnia.I don't claim to be a feminist, but I'd like to see more women in managerial posts.
claim to have done something
Two young girls claim to have seen the fairies.
claim responsibility/credit (for something) (=say officially that you are responsible for something that has happened) The group claimed responsibility for a series of bombings.Opposition leaders will claim victory if the turnout is lower than 50%.
claim somebody/something as something
A letter appeared in The Times claiming Fleming as the discoverer of penicillin.

所以这个题一上来直接排除A和B 然后在C D E中选

补全了，能不能再帮我分析一下它的结构，以及逗号之后的部分是什么成分？