题目

根据短文理解，选择正确答案。 Some 30,000 years ago, artists who lived in caves in Europe painted pictures of the animals around them: panthers, hyenas, rhinos, cave lions, mammoths and other creatures which have been extinct for a long time. The paintings were highly realistic. Some even showed movement. The artwork, more than a thousand drawings, is considered the oldest group of human cave drawings which have ever been discovered. They were preserved because the cave was sealed—closed off--for more or less 23,000 years. Fast forward to December 18, 1994, a group of French cav（1）计算：．（2）如图：△ABC中，DE∥BC，试说明△ADE∽△ABC．