What does XD mean? I keep seeing people say it and I dont know what it means

Which of the statements below is true? the formatting, standard, and drawing commands are unavailable. the formatting, standard, and drawing commands have been used. the formatting, standard, and drawing toolbars are displayed. the formatting, standard, and drawing toolbars are hidden.

You are asked to calculate an object's velocity, in order to do so you must know the object's a. direction and speed. b. distance and time. c. speed and distance. d. direction and distance.

Which of the following methods could be considered a “best practice” in terms of informing respondents how their answers to an on-line survey about personal information will be protected? the investigator uses the informed consent process to explain how respondent data will be transmitted from the website to his encrypted database without ever recording respondents’ ip addresses, but explains that on the internet confidentiality cannot be absolutely guaranteed. respondents are informed that investigators will try to keep their participation confidential; however, confidentiality cannot be assured. the investigator uses the informed consent process to explain her institution’s method for guaranteeing absolute confidentiality of research data. respondents are informed that a research assistant will transfer all the research data to a password-protected computer that is not connected to the internet, via a usb flashdrive. the computer is located in a research team member’s office.