use one thing for many purposes / work someone hard

to use one's head

pedestrian

moving average

mobile phone

teleportation

(education) instruction that takes place outside of a classroom (field trip, etc.) / (education) class that takes place in its own specialized room instead of homeroom (such as music or cooking)

precious articles / valuable item / treasure / ornaments / relic / outstanding individual

device; instrument / container; vessel

device; instrument