The tissues of the human body are constantly moistened by a briny solution thought to be of about the same salinity as the primordial sea from which life emerged.
(b)of as about the same salinity like the primordial sea out of which
(c)to be about the same salinity as the primordial sea from where
(d)of as about the same salinity as the primordial sea from where
(e)to be of about the same salinity like the primordial sea from which
答案是(a) 其實這一題看的不是很懂 另外劃線部份的of所扮演的角色為何呢?