Why is the osi reference model useful? a. because the osi creates standards that network engineers need. b. because it means all network equipment is built to the same standard. c. because it can be applied to a network to solve anything that goes wrong. d. because it provides troubleshooters a shared frame of reference. useful?

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