题干

生物与环境紧密相关.下列关于生物与环境的说法,正确的是(  )

A:在一定的空间范围内,生物与环境所形成的统一的整体叫做生物圈

B:秋天树木纷纷落叶,这是生物对环境的影响

C:峨秀湖属于农田生态系统

D:食物链的起始环节是生产者

上一题 下一题 0.0难度 选择题 更新时间:2015-12-30 05:51:29

答案(点此获取答案解析)

D

同类题2


 We all know that exercise is good for your health. But some kinds of exercise may be better than others. Running, for example, may help to protect against heart disease and other health problems. Running may also help you live longer.

 Recently, researchers studied more than 55,000 adults. About a quarter of the adults have a good habit of running. The study found these runners were much healthier than non-runners. In fact, the runners lived, on average(平均), three years longer than the non-runners.

 Running may be good exercise, but it can be difficult on the body. Here are commonly shared ideas among fitness experts(健身专家) to lower the risk of injury(受伤) for people who are new to running.

⊙Take it easy.

 Do not run too much, too soon or too fast. Most people get running injuries when they push themselves too hard. The body needs time to get used to increases in distance(里程) or speed.

⊙ Get good running shoes.

 There is no single best shoe for every runner. You should find the shoe that offers the best fit and support for your feet. More importantly, you should have a new pair of shoes every 500 to 800 kilometers.

⊙Take good notes.

 Take time after each run to write down notes about what you did and how you felt. Look for things that happen again and again. For example, you may find that your knees hurt when you run sometimes. But perhaps you feel great when you have a rest between running days. These notes will help you make the best plan for running.