15. The sign means:

A. Be careful, it’s easy to catch fire.

B. Burning something is not allowed.   

C. No picnicking allowed.

D. Keep away from fire.

16. You often see this sign on an electric pole, it means:

A. Be careful of lightning!                   

B. For high voltage devices!  

C. Danger, no climbing!                                 

D. Stay under the arrow!