Question

__________ some maddals came to live in the sea is not

1. A.
   Which
2. B.
   Since
3. C.
   Although
4. D.
   How

Answer 1

D
该句的从句由疑问副词how引导的主语从句。选项B、C中的since和a1though不能引导主语从句；选项A中的which虽能引导主语从句，但与some矛盾。