Interaction 2 Listening And Speaking Answer Key -

Hi all,

I'm using ST's CubeMX implementation on a F4 discovery board. I use ST's USB middlewares with FreeRTOS.

When I get a special OutputReport from PC side I have to answer nearly immediately (in 10-15 ms). Currently I cannot achieve this timing and it seems my high priority tasks can interrupt the USB callback. What do you think, is it possible? Because it's generated code I'm not sure but can I increase the priority of the USB interrupt (if there is any)?

Thank you, David

10 to 15 ms is very slow, so I'm sure its possible.

Where is the USB callback function called from? If it is an interrupt then it cannot be interrupted by high priority RTOS tasks. Any non interrupt code (whether you are using an RTOS or not) can only run if no interrupts are running.

Without knowing the control flow in your application its hard to know what to suggest. How is the OutputReport communicated to you? By an interrupt, a message from another task, or some other way?

The callback which receive the data from PC is called from the OTGFSIRQHandler (it's the part of the HALPCDIRQHandler function). I think the problem is SysTickHandler's priority is higher than OTGFSIRQHandler and it's cannot be modified, but the scheduler shouldn't interrupt the OTGFSIRQHandler with any task handled by the scheduler. Am I wrong that the scheduler can interrupt the OTGFS_IRQHandler?

For decades, the Interaction 2: Listening and Speaking textbook (part of the renowned Interactions/Mosaic series by McGraw-Hill) has been a cornerstone in English as a Second Language (ESL) and English as a Foreign Language (EFL) curricula worldwide. Designed for high-intermediate learners, this book bridges the gap between classroom English and real-world conversational fluency.

However, anyone who has used this textbook knows the challenge: self-assessment is critical. This is where the becomes an invaluable tool. Whether you are a self-study student, a tutor, or a classroom teacher, having access to verified answers ensures that you are learning correct pronunciation, note-taking strategies, and conversational techniques.

A: The answer key includes phonetic transcriptions for minimal pairs (e.g., ship vs. sheep ). Use Google’s speech-to-text or an app like Elsa Speak to see if the app recognizes your word. Conclusion: Use the Key as a Tool, Not a Crutch The Interaction 2 Listening and Speaking answer key is a powerful resource for high-intermediate English learners. When used wisely—to analyze errors, study transcript clues, and emulate model speaking responses—it accelerates your path to CEFR B2/C1 fluency.

A: Yes, but they are model responses , not exact scripts. The key says, "Answers will vary. Acceptable responses should include X, Y, and Z."

However, remember that real-world conversations do not come with answer keys. Use the textbook’s structured practice to build confidence, but finally, turn off the audio scripts and talk to a human. That is the ultimate test of listening and speaking mastery.

Looking for more resources? Check your local college bookstore for the official "Interaction 2 Audio Tapescripts" or explore McGraw-Hill’s online student center for interactive listening quizzes. This article is for educational guidance purposes. For copyright reasons, specific verbatim answers are not reproduced here. Please purchase the official Teacher’s Edition from McGraw-Hill for complete answer keys.

Thank you for the answer, I think I'm a bit confused with the Cortex ISR priorities :-) What I can observe is if I use a much higher osDelay in my high priority task I can respond for the received USB message much faster. This is why I think tasks can mess up with my OTG interrupt.