四年级科学 （动物的呼吸器官）

Insects breathe through tiny openings called spiracles, which are located on the sides of their abdomen. These spiracles allow air to enter the insect's respiratory system and deliver oxygen to their cells. Therefore, the correct answer is "腹部" (abdomen).

The question states that the animal has two respiratory organs, which allows it to live in water for a long time without needing to come to the surface frequently. Among the given options, sea turtles are known to have adaptations that enable them to stay underwater for extended periods. Sea turtles have specialized lungs that allow them to extract oxygen from the water and can hold their breath for long periods. Therefore, sea turtles are the most likely animal that fits the given description.

The correct answer is "鳄鱼" because all the other animals listed (青蛙, 蝾螈, 蟾蜍) are amphibians and have only one respiratory organ, which is their lungs. In contrast, 鳄鱼 is a reptile and has both lungs and gills, allowing it to breathe both in water and on land.

The correct answer is 蟾蜍 (Toad). The description provided matches the characteristics of a toad. Toads have lungs for breathing, but they can also absorb oxygen through their moist skin. They live on land but can also live in water.

The correct answer is X: 鳃 Y: 肺, 潮湿的皮肤. This is because the image shows the animal transitioning from having gills (鳃) in the X stage to having lungs (肺) and moist skin (潮湿的皮肤) in the Y stage.

The incorrect statement is "蚯蚓用潮湿的皮肤和肺呼吸" (Earthworms breathe through their moist skin and lungs). Earthworms do not have lungs, but instead, they breathe through their skin. They do not require a moist environment to respire, but they do need a moist skin surface for gas exchange to occur effectively.