A:We have some meat for lunch.
B:We have some chicken for lunch.
计算:(+6.2)﹣(+4.6)﹣(﹣3.6)﹣(﹣2.8)
欧洲西部的区域性国际组织是( )
发光二极管俗称LED,如图所示,把LED接入电路,闭合开关后LED正常发光,用手触摸几乎不发热.以下说法正确的是( )