题目

认识生物多样性面临威胁的主要原因，有助于更好地保护生物多样性 （1） 生物多样性面临威胁的主要原因有：①滥砍乱伐 ②滥捕乱杀 ③环境污染 ④外类物种入侵在长江生存繁衍了两千多万年的白鳍豚走向灭绝的主要原因是（请填序号）生活在西藏、新疆、青海三省的藏羚羊濒临灭绝的主要原因是（请填序号） （2） 建立自然保护区是保护生物多样性最为有效的措施．为保护完整的温带森林生态系统我国建立了自然保护区；我国建立四川If you think you’ve gained too much weight or are too skinny, you can talk to a doctor. Your doctor will tell you _1.__.If it is concerned about your height, weight, or BMI(体重指数)，your doctor may ask questions__2.__. Your doctor may also ask about your family background to find out if you’ve received something from your parents that might make you taller, shorter, or a late bloomer(someone who develops later than other people of the same age). The doctor can then put all the information together to decide _3.__.If your weight isn’t in a healthy range, you will probably get specific diet and exercise recommendations (推荐)based on our individual needs,. Following a doctor’s or dietitian’s plan designed especially for you will work much better than following fad(时尚) diets. For teens, fad diets or starvation plans can actually slow down growth, and the weight loss usually doesn’t last.What _4._? Most teens who weigh less than other teens of their age are just fine. They may be going through puberty on a different schedule than kids of the same age, and their bodies may be growing and changing at a different rate. Most underweight teens catch up in weight as they finish puberty during their later teen years so there’s rarely a need to try to gain weight.In a few cases, teenagers can be underweight because of a health problem that needs treatment. If you feel tired or ill a lot, or __5.__, or other problems that have lasted for more than a week or two, be sure to let your parents or your doctor know.A.whether you might have a weight or growth problemB.if you have symptoms (症状)like a cough, stomachache.C.about your health, physical activity, and eating habitsD.if you’re worried about being too skinnyE.if you take care of itF.whether you’re growing normallyG.about your dieting