Part I Listening Comprehension (20 minutes) Directions: In this section, you will hear ten short conversations At the end of each conversation, a question will be asked about what was said. both the conversation and the question will be spoken only once. After each question there will be a pause During the pause, you must read the four choices marked A), B), C)and D),and

Part I Listening Comprehension (20 minutes) Directions: In this section, you will hear ten short conversations at the end of each conversation, a question will be asked about what was said. both the conversation

Part I Listening Comprehension (20 minutes) Directions: In this section, you will hear ten short conversations. At the end of each conversation, a question will be asked about what was said. both the conversation and the question will be spoken only once. After each question there will be a pause During the pause, you must read the four choices marked A), B), C)and D), and decide which is the best answer

Listening Comprehension(20 minutes) Section A Directions: In this section, you will hear 10 short conversations. At the end of each conversation, a question will be asked about what was said. Both the conversation and the question will be spoken only once. After each question there will be a pause. During the pause, you must read the four choices marked A), B), C) and D), and decide which is the best answer. Then mark the corresponding letter on the Answer Sheet with a single line through

Part Listening Comprehension (20 minutes) Directions: In this section, you will hear ten short conversations. At the end of each conversation, a question will be asked about what was said. Both the there will be a pause. During the pause, you must read the four choices marked A),),C) and D),and decide which is the best answer. Then mark the corresponding letter on the Answer Sheet with a single line through the center

Part I Listening and Speaking Activities Introduction of functions Listen and speak Try to speak more Make your own dialogue What are they for? If you want to learn more

Part I Listening and Speaking Activities Introduction of functions Listen and speak Try to speak more Make your own dialogue What are they for?

Objectives Focus A. What do you say? B. Vocabulary C. Reading D. Listening

Carrier Sense Multiple Access(CSMA) In certain situations nodes can hear each other by listening to the channel “Carrier Sensing CSMA: Polite version of Aloha Nodes listen to the channel before they start transmission Channel idle=> Transmit Channel busy = Wait (join backlog) When do backlogged nodes transmit? When channel becomes idle backlogged nodes attempt transmission with probability q=1 Persistent protocol, q=1 Non-persistent protocol,< 1

Part I: Listening Comprehension(15% (20 minutes Section A Directions: In this section, you will hear 10 short conversations. At the end of each conversation, a question will be asked about what was said. Both the conversation