A、  B、  C、  D、  A

(A)He’s opening the door.
(B)He’s sitting upright in a chair.
(C)He’s working with a tool.
(D)He’s taking off his running shoes.

(A)He has taken a seat at a workstation.
(B)He is tidying up his work area.
(C)He’s turning on the computer.
(D)He’s about to sit in the chair.