Your lecturer asks you to pick up a guest speaker at the airport. Since you never see him/her, then you ask for clarification. Here, you ask your lecturer how he/she looks like. Ask the guest’s physical characteristics, such as : the height, build, age, hair, face, skin color or complexion, eyes, and specific characteristics like wearing spectacles, having dimples, or wearing a bowler hat, etc. To make sure, you repeat what the lecturer has told you, then the lecturer agrees. At last, end the conversation and promise you won’t miss the guest.