______ how the splendid Maya Culture disappeared all of a sudden from the earth,it remains a mystery hard to solve.
A.In turn B.As to C.Thanks to D.As a rule正确答案B
______ how the splendid Maya Culture disappeared all of a sudden from the earth,it remains a mystery hard to solve.
A.In turn B.As to C.Thanks to D.As a rule正确答案B
