读一读，找出每组单词中不同类的一个。（10 分）
(1)A. by ship        B. by plane         C. go home
(2)A. hospital       B. museum           C. helmet
(3)A. turn right      B. turn left        C. on foot
(4)A. stop           B. wait             C. sled
(5)A. must           B. often            C. sometimes