一只3Ω的电阻和一只6Ω的电阻,它们串联起来后的总电阻为____ Ω,它们并联起来后的总电阻为____ Ω.
Tom rode his motorbike to work yesterday and had a crash with a car. His motorbike was ________ and he was seriously ________.
葡萄糖是细胞进行有氧呼吸最常利用的物质。将一只实验小鼠放入含有放射性18O2气体的容器中,18O2进入细胞后,最先出现的放射性化合物是( )