题干

某生物兴趣小组的同学用河水、池泥、水藻、植食性小鱼、广口瓶、凡士林等材料制作了3个生态瓶(如图所示).下列说法中错误的是(    )

A:甲瓶中的小鱼很快死亡是因为瓶内分解者数量过少

B:乙瓶中的生物存活的时间相对较长

C:丙瓶中的分解者主要存在于河水及池泥中

D:若想维持稳定性,丙瓶不应放在黑暗中

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答案(点此获取答案解析)

A

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完形填空

     People have been raising pigeons(鸽子) for about 10,000 years. And pigeon  keepers use  different kinds of pigeons for different 1Some people use pigeons for 2 For example, in parts of China people cook a special meal with pigeon to celebrate the New Year.

Some people also keep pigeons because they look especially 3There are many interesting kinds of these “pretty” pigeons. Different kinds of pigeons have interesting features 4 long, soft tail feathers or designs on their heads. The owners of these kinds of pigeons enter them in 5  and the best looking pigeons are chosen to win prizes.

     But pigeons have many othe6   too. Pigeons can fly long distances without growing 7 . They also have another8sense. No matter how far from home they are, pigeons can usually fly back to where they9This is often called a “homing sense”. This sense makes them good for carrying10

     In many cities around the world, pigeons live in special houses, and pigeon keepers spend a lot of money and time11 their birds. When someone has a very good pigeon, he is very12    He may also have a way to make money.  But this is not usually the main13 people keep pigeons. For some people, they keep pigeons as a hobby.

     People love pigeons so much that they even take them14 when they move to a new country. They15 these birds as their children.  “When you are looking at a pigeon in the sky you feel free. It is the best feeling you have in a strange country”, a pigeon lover says.