题干

根据所学知识回答:
(1)鱼所以能在水中生活,最重要的两个因素是:一是能在水中____ ,二是能靠____ 来获取食物和逃避敌害。观察鲫鱼时,我们看到鲫鱼的身体呈____ 形,这种体形在它游泳时可以起到减小____ 的作用。
(2)与家兔相比,蚯蚓不能快速运动的原因是只有肌肉没有____ 。
(3)在观察蚯蚓的实验中,要保持蚯蚓体表的湿润,其原因是____ 。
(4)青蛙是两栖动物,其幼体生活在水中用____ 呼吸;成体水陆两栖生活,用____ 呼吸,同时用皮肤辅助呼吸。

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答案(点此获取答案解析)

呼吸,游泳,梭形,阻力,骨骼,蚯蚓靠湿润的体壁呼吸,鳃,肺

同类题3

完成表格, 每空一词。

    You must hear about earthquakes, but do you know what to do during and after an earthquake? Here is some advice for you:

Before an earthquake. It is necessary to prepare yourself and your family. All family members should know how to turn off gas, water and electricity and know useful telephone numbers (doctor, hospital, police, 119etc). Never put heavy things over beds.

During the earthquake. It's important for each of you to stay calm. If you are indoors, quickly move to a safe place in the room such as under a strong desk or a strong table. It can protect yourself from falling things. Stay away from windows, large mirrors, heavy things and so on. If you are cooking, turn off the gas.

    If you are outdoors, move to an open area like a playground. It's important to move away from buildings, bridges and trees. If you are driving, stop the car as soon as possible. Stay in your car.

After an earthquake. Once the shaking stops, do not run out of the building at once. It's better to wait and leave when it is safe.

Check around you and help the people in trouble. If your building is badly broken, you should leave it. If you smell or hear gas, get everyone outside and open windows and doors. If you can do it safely, turn off the gas. Report it to the gas company.

Some useful ____ about earthquakes


Before an earthquake

____ yourself and your family.

Don't ____ to turn off gas, water and electricity.

Remember some useful telephone numbers and not to____ heavy things over beds.




____ an earthquake

____ calm is important for each of you.

Moving to a safe place in the room can protect yourself from falling things if you are ____.

Remember to turn off the gas if you are cooking.

Moving to an open area and away from buildings is____ if you are outdoors.

Remember to stop your car and stay in it if you are driving.


After an earthquake

Run out of the building ____ it's safe.

Check around you and help the people in trouble.

Leave your badly broken building.

Keep everyone outside and the windows ____ if you smell or hear a gas.