Read the sentence. Conducting experiments is a very exciting part of the science classroom.

safety must be the first concern of students and teachers.
Which transition best fits the pair of sentences?
А. Therefore,
B. For example,
с. On one hand,
D. However,

samuel gompers was an extremely important person in the american labor movement, being him an employee all his life he devoted himself to fight for the rights of his pairs, he believed they all had the right to have better thing and that they all were working for them but the factory workers were greedy, ambitions and socialist people for him who he didn't have a good concept of.

he gave so many speeches and led so many strikes and protest to fight for equality which he considered employers didn't want to accept, so he had an absolutely negative opinion of them.

every person should make it a priority to serve at least two hours per week.

it's an extremely important civic responsibility that is invaluable to citizens most in need is the correct one