15. What does the sign mean?

A. Ride a bike to throw a car away.

B. Ride a bike and play with a toy car.

C. Take a ride around the bin.

D. Travel by bike instead of by car to save energy.

16. What does the sign mean?

A. Driving speed is restricted to 50km/h.

B. Your driving must exceed the speed of 50km/h.

C. Your driving must be 50km/h above speed limit.

D. The minimum speed of a vehicle cannot get lower than 50km/h.