求助0508的几道题，谢谢！

uspresidentUID: 2123602

14. Nitroglycerin is an unstable chemical compound that is very sensitive sudden movement -------dangerous to transport
(A) because
(B) and therefore
(C) why it is
(D) making
为什么选B啊？and后面没有谓语动词阿？
38. Seamounts are isolated submarine mountains believed to be the remnants of extinct volcanoes that either formed or sank far beneath of the ocean surface.
beneath of难道不对吗？谢谢！
阅读：
Maury believed that the circulation of a warm current would produce ice-free sea around the North Pole, a claim not disproved until Fridtjof Nansen allowed his vessel The Pram to be carded to within a few degrees of the pole in the years 1893-1896.
49. The passage suggests which of the following about the visit of The Fram to the North Pole?
(A) Matthew F. Maury was aboard The Fram when it traveled to the North Pole.
(B) During The Pram's visit to the North Pole. Matthew F. Maury's belief about the North Pole's sea was tested.
(C) The discoveries of The Pram were later refuted by Matthew F. Maury's discoveries.
(D) The Pram found that the water surrounding the North Pole was ice free.
怎么会是B呢？明显是a claim not disproved until，应该是被反驳啊，不是证实阿！谢谢！

avexUID: 159089

14.省略is
38.去掉of
49.这道题考的就是test，所以说现在加难的是选项
    无论是prove to be ture还是wrong都是test
    也就是MFM的理论是被检验，但选项没有说结果是对还是错
    然后A是无稽之谈，文章根本没说MFM上过船

uspresidentUID: 2123602

明白了，谢谢！