What is something that makes you happy here are some things that make me happy❤️

In order to take a test,the college board requires a form of identification. these strict rules are in place to keep people from taking other people's test. 

Which of the following is an example of an opposing signal? no examplthates given.   i would say, that traffic lights in a city at major intersections direct the flow of traffic in opposite directions so would be an example.also, stop signs on either side of the same street would be an example. at a train crossing, the light for allowing car traffic in opposite directions or not would be another example.