英语九年级U15 help1.----I usually go home by ship ----why not ___

英语九年级U15 help
1.----I usually go home by ship
----why not ____by air for a change
A.trying to go B.trying going C.try going D.try to go
2.this is a ____river and that river is ________
A.200-metre-long ;200metre long
B.200-metre-long ;200metres long
C.200-metres-long ;200metres long
D.200 metres long ;200-metre-long