You can go to school by _____. It snows a lot.
A.sled B. ferry C. plane
I must ______ the traffic lights.
A.look after B. pay attention to C. look for
There is a picture _____ a bike.
A.in B. of C. at
In the USA, people on bikes must ____ a helmet.
A. on B. put on C. wear
There are always three lights: red, yellow and ______.
A. green B. blue C. orange