33.
Your Answer is
Correct Answer is A
Explanation
The previous sentence mentioned that "Other scientists soon confirmed that a 65-million-year-old iridium layer existed around the Earth", and the latter sentence should read "Alverezes hypothesized that a huge extraterrestrial object must have hit the Earth in the past, leaving behind The lower iridium is everywhere thousands of miles away".
Item A: According to the logical relationship between the upper and lower sentences, somewhere modifies the verb crashed correctly.
Item B: "to some extent", does not match the relationship of the previous sentence.
Item C: "More or less", does not match the relationship in the previous sentence.
Item D: "However", does not match the relationship in the previous sentence.