题目

阅读理解 An increase of just 2℃ in global temperatures could make the world considerably drier and more desert-like, new research has warned. More than a quarter of theworld's land surface, home to more than 1.5 billion people, would become morearid and droughts and wildfires could be widespread. Limiting global warming to1.5℃ would dramatically reduce the percentage of the Earth's surface affected,scientists found. Aridification (干旱化) would emerge over 20 to 30 percent of the world's land surfaceby the time the global temperature change reaches 2℃，said Dr Manoj Joshi from th已知：如图，ABCD中，对角线AC、BD相交于点O，则图中全等的三角形有________≌________；________≌________；________≌________；________≌________．