Fill blank (iv).

Directions: The following passage has some numbered blanks.

Naval architects never (i) ___ that a ship is unsinkable, but the sinking of the passenger-and-car ferry Estonia in the Baltic surely (ii) ____ have never (iii) ____. It was well (iv) ____ and carefully maintained. It carried the proper number of lifeboats. It (v) ____ thoroughly inspected on the day of its (vi) ____ voyage. Yet hours later, the Estonia rolled over and sank in a cold, stormy night. It went down so (vii) ____ that most of those (viii) ____, caught in their dark, flooding cabins, (ix) _____ no chance to save themselves. Of those who managed to (x) ____ overboard, only 139 survived. The rest died of (xi) _____ before the rescuers could pluck them from the cold sea.