46.

Answer and Explanation

Your Answer is

Correct Answer is H

Explanation

what= noun + that/which, here on what is known as = on the place which is known as, so H is correct.

Item F: In the first case, the adverbial clause of when leading time is not established, because it does not conform to the logic of the sentence. In the second case, the attributive clause guided by when is also not valid, because the clause guided by when does not modify the previous noun feet.

G item: that guides the attributive clause to modify the preceding noun 10,000 feet, which does not match the semantics. Here it does not mean "Herodotus Abyssal Plain is below 10,000 feet under the sea", but "under 10,000 feet under the sea A place called Herodotus Abyssal Plain".

Item J: The attributive clause guided by on which cannot be the subject in the clause, so it is wrong.