题目

细胞是构成“生命大厦”的基石，每时每刻都在进行着各种各样的生命活动。请回答： （1） 自然界中，大多数生物都是由许多细胞组成的，称为多细胞生物。多细胞生物起始于一个细胞，为细胞。这个细胞通过使细胞数目增多，通过产生各种组织。 （2） 细胞的生活离不开物质。细胞生活需要的多种营养物质进入细胞，自身产生的废物排出细胞，都要经过，它控制着物质的进出，使细胞拥有一个比较稳定的内部环境。 （3） 细胞的Being fit is a way of saying a person eats well,gets a lot of physical exercise,and has a healthy weight.There are a lot of discussions these days about fit kids.【1】1.Eat a variety of foods.You may have a favorite food,but the best choice is to eat a variety.【2】Taste new foods and old ones you haven’t tried for a while.Some foods,such as green vegetables,are more pleasing the older you get.Shoot for at least five servings of fruits and vegetables a day-two fruits and three vegetables.2.Listen to your body.What does it feel like to be full?When you're eating,notice how your body feels and when your stomach feels comfortably full.Sometimes,people eat too much because they don't notice when they need to stop eating.【3】And over a period of time,overeating can lead to unhealthy weight gain.3.【4】.What’s screen time?It’s the amount of time you spend watching TV or DVDs,playing video games,and using the computer.The more time you spend on these sitting-down activities,the less time available for active stuff, like basketball,bike riding and swimming.【5】These rules aren’t magic.However,follow them most of the time and you can become a fit kid sooner or later.A.Limit screen time.B.If you're a kid who wants to be fit,here are three rules to live by.C.Drink water and milk.D.Ask your parents to help you do your favorite activities regularly.E.Eating too much can make you feel uncomfortable.F.If you eat different foods,you're more likely to get the nutrients your body needs.G.Try to spend no more than 2 hours a day on screen time.