wrote her letters in a colloquial style / the broken syntax and casual enunciation of conversational English Similar: informal (used of spoken and written language)
Best Answer: The mid-oceanic ridge can be described as the longest mountain range. It includes the Mid-Atlantic ridge, and all other such ridges. They form a complete system that is 65000 km long. The Mariana's Trench is the deepest. It's 11.03 kilometres deep. I don't know how you define underwater mountain.
Note: The dormant volcano Mauna Kea (on the Big Island of Hawaii) could be considered the tallest mountain in the world. If you measure it from its base in the Hawaiian Trough (3,300 fathoms deep) to its summit of 13,796 feet, it reaches a height of 33,476 feet.