1. (2022·江山模拟) 阅读下面材料，根据文中信息完成对比图。任务 A：补全 信息。每空限填一词。任务 B：回答问题。不超过 10 个词。

There are about 250 kinds of turtles. Most turtles live near fresh water. However, land turtles, also known as tortoises, do not swim at all. Sea turtles live nearly their whole lives in salt water.

Tortoises

Tortoises are slow. They have short, thick back legs. Their front legs are very good for digging. Many tortoises can pull their heads, legs, and tails inside their shells. They quickly do so at any sign of danger. Their strong shells can protect them. Unlike most other turtles, tortoises eat only plants. Tortoises hatch from eggs. The mother tortoise digs a hole, lays some eggs, and covers them with earth. When the baby tortoises hatch, they must dig their way out of the hole. The largest tortoises can grow to four feet long. They may weigh up to 600 pounds.

Sea Turtles

Like tortoises, sea turtles lay their eggs on land. The mother turtle comes out of the ocean onto the beach. She digs a hole, lays her eggs, and returns to the sea. When the baby turtles hatch, they head straight for the water. Sea turtles can swim very fast. They use their front legs like wings to "fly" through the water. Although most turtles can pull their heads and legs inside their shells, sea turtles cannot. The green sea turtle eats only plants. Other sea turtles eat both plants and animals. The largest of all sea turtles can weigh over 1,000 pounds.

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When will tortoises pull their heads and legs inside the shells?