Traveling------ air is much faster than traveling --- sea.a.

两个都要填by
air在此处意为飞机,sea意为轮船.
交通工具前用by,表通过某种工具做某事.
本句意为 坐飞机比坐轮船旅行快很多.
再问： Thanks a lot of ____(make)English. I ___(go) t Canada next week
再答： 介词后跟现在分词，of为介词，故填making next week 为将来时态时间状语，填will go或is going to go 希望对你有帮助。