桥有很多种,有独木桥、竹桥、拱桥、吊桥等。它们为人们解决了过河的问题,给人类带来了极大的方便。最原始的是独木桥。人们为了渡河,把河岸上的树木砍下来,架在两岸,就做成了独木桥。后来人们加以改良,用智慧和双手,慢慢地使桥发展到现在的多种形式。桥不仅让人过河方便,还能 There are many kinds of bridges, a single wooden bridge, bamboo bridge, arch bridge, suspension bridge. They solved the problem of crossing the river for people and brought great convenience to mankind. The most primitive is a single wooden bridge. In order to cross the river, people cut down the trees on the banks of the river and racked them on both sides of the river to create a single-plank bridge. Later, people improved, with wisdom and hands slowly to bridge development to the present various forms. Bridge not only convenient for people to cross the river, but also