21. What do police officers, construction workers, and school crossing guards have in common?
A. They all must sometimes work near traffic.
B. They are all at a higher risk from impaired drivers.
C. Each is always protected by warning signs.
D. A and B

How can you tell that you're driving in the right direction? options are a. there is a white line on your left and a yellow line on your right. b. there are yellow lines on both sides of your vehicle. c. there is a double yellow line on your right. d. there is a yellow line on your left and a white line on your right.