The correct answer is A. have been
This is a linking verb that provides the aspect of the main verb that is careful. Should is a modal verb.
Calculators are to past generations as computers are to current generations.
<span>1. They underscore the fact that everyone makes mistakes. In modern vernacular, Shakespeare is saying 'if I made a mistake, and you can prove it, I won't complain.'</span>
Is taht all of the story or is that it
By explaining problems and giving solutions! this is the best fit because the other two might make sense at a first glance, but only explaining problems and solutions would be an effective way to teach people how to set up an aquarium by giving them examples of what to do and what not to do whereas the others are just him talking about his aquarium.
