Question

1.Canada lie ---- America,north -----the USA.

Answer 1

...应该是a..Canada lies in the America,north of the U.S.A.

因为后面那半句一定得是north of the U.S.A.所以答案只剩下b and c..but Canada is a country,you can't use "at" to describe a country..So it should be "in",