Miss Fang: Hello, children. This is Mr. Xu. He's a fireman. Let's welcome Mr. Xu.

Mr. Xu: Thanks. Let's talk about ____safety today. Fire can burn down trees. It can ____people, too. We must be ____with fire. What mustn't we do in the forest or at home, children?

Peter: We mustn't ____in the forest.

Kitty: We mustn't play near fires or play with ____at home.

Mr. Xu: Very good. Safety first.

本初子午线是（　　）

阅读下列材料：

我们以这些殖民地的善良人民的名义和权力，谨庄严宣告：这些联合殖民地从此成为、而且名正言顺地应当成为自由独立的合众国，它们解除对英王的一切隶属关系，而它们与大不列颠王国之间的一切政治联系也应从此完全废止。

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