A majority of the international journalists surveyed view nuclear power stations as unsafe at present but that they will, or could, be made sufficiently safe in the future.
好久没看语法题了,偶的一点个人意见,从解题的角度讲,抛开that的问题,以及will,would在本题的差异,如果or could做插入语,应该在前后加上逗号才可以,即power station would, or could, be ...,否则就应该再will后面加上be,成为will be or could be...