When the girl is cycling, her head gets hot. The skin on her head sweats. Suggest how the structure of the helmet helps the sweat on her head to evaporate.

co2reflects heat radiation back to earth buning coal and oil emits co2 globe warms

a is the best answer your welcome

the only real purpose of sputnik 1 was to beat the us into space. we were getting close to launching a useful satellite, explorer 1 - which launched on january 31, 1958. the ussr had to beat that, so they launched sputnik 1 on october 4, 19

there are no contact forces mentioned on the list of choices that you've provided.