题目

It is not as simple as opening the door and hitting the track in winter. There are a few things you can do to ensure you are getting the most out of your run, and, importantly, not doing more harm than good.Warm up, cool down【1】Your muscles need some time to warm up when it’s cold, so take it easy when you set off and do a few stretches (伸展) once you're finished.Drink waterYou might not feel hot, but that's because sweat evaporates (蒸发) more quickly into the chilly, dry air. So be sure to drink water before, during and after cold-weather workouts.【2】A belt bottle conveniently克隆羊多莉的遗传物质主要来自于（　　）A．供细胞核母羊B．供卵细胞羊C．代孕母羊D．无核卵细胞