Thousands of years ago people discovered
问题:
Thousands of years ago people discovered the phenomenon by chance, and this was _____ the idea of the compass first came from.
A.how
B.what
C.where
D.that
Thousands of years ago people discovered the phenomenon by chance, and this was _____ the idea of the compass first came from.
A.how
B.what
C.where
D.that