During the speech introduction, the audience decides whether they are interested in the topic and the speaker. to build credibility, a speaker should establish his or he

qualifications

Explanation:

To attract the  audience and to make them interested in the topic of your speech, a speaker should give a first good impression at the speech introduction. There various ways to start a speech that would gin immediate attention like quotes, shocking statements, etc. Equally important is to establish a credential position by the speaker. He should tell his audience about the knowledge and credentials he holds to increase his credibility to speak on that topic.

two jet streams that directly affect the formation of weather in the continental part are a polar jet and a subtropical jet. they are responsible for the transportation of weather systems, which directly affect people. the polar front is the boundary between cold air from the north pole and warmer equatorial air. both the polar jet and the subtropical jet blow from the west to the east, and follow the boundary between cold and warm air.

the strongest jet streams are polar jets, while subtropical jets are somewhat weaker.

the right answer is c. the polar jet stream is generaly stronger than the subtropical jet stream.