M:I figured it all out. It looks like it'll take us a few days to walk from Alpine lake to Henderson Glacier.
W:It'd be easier to go in from the back route. But i guess we should check the map first.
Q:what can be inferred about the speakers?
A)They are on a boat.
B)They are skating.
C)They are hiking.
D)They are driving a car.
ANS:C
請問一下,如何知道答案是c呢?