The study of sound and sound wave is called​

Need asap write a short paper describing the history and differences between six sigma, waterfall, agile, and scrum models. understanding these models can give you a good idea of how diverse and interesting it development projects can be. describe what the rationale for them is and describe their key features. describe the history behind their development. at least 400 words

Your computer running windows 10 is doing some very strange things with the operating system. you are fairly certain it is not a hardware issue. you need to try to get further insight into what is going on within the operating system. which tool would be best-suited for this?

Dereck works for long hours on his computer.  he frequently experiences physical strain by the end of the day because he does not follow an important rule of ergonomics with respect to the use of keyboards.  which of the following actions of dereck could lead to physical strain? a.  placing the keyboard exactly in front of him while typingb.  keeping hands and wrists straight while typingc.  using wrist pads throughout the dayd.  pounding at the keys on the keyboard while typinge.  resting his hands on the keyboard when he is not typing