Learn the Present and Past Tenses of 'To Do' in English

Kai One, 凱文 | Snowboard Groundtrick and Butters on Instagram: "Having a good warm up routine will help prevent injury and also help you preform better. Once you start treating snowboarding as a sport you will become a different rider. Model: @_souleysasha_ Snow Pants: @xasha_xasha"

physicsfun on Instagram: "Iridescent Dual Spiral: another fun 3D print with dual spiraling motion this time using tricolor iridescent silk filament that produces a color changing effect. More kinetic art from RJ Design. ➡️ Follow the link in my profile for info on where to get this inexpensive kinetic art (or the stl files) and many other amazing items featured here on @physicsfun #helix #kineticart #physicstoy #illusion #spinner"