The mechanism one uses to transmit a message is known as the __________

Which of the following use(s) prepositions accurately?

A) We will eat dinner at seven o?clock. B) We will eat dinner by seven o?clock. C) We will eat dinner in seven o?clock. D) both A and B

As the mayor of a town, Jim was asked to speak at the graduating ceremony of a batch of students from the community college. He addressed 150 students, appreciating them for their admirable performance in their finals. He urged them to always reach for the stars and nothing less. His speech ended with much appreciation and applause from the entire audience. In this scenario, Jim was offering a

_____. A) ?keynote address B) ?commencement address C) ?farewell D) ?commemorative address