关于地球自转方向的准确说法是( )
A:顺时针方向
B:逆时针方向
C:自西向东
D:自东向西
如图,⊙O为△ABC的内切圆,∠C=90°,AO的延长线交BC于点D,AC=4,DC=1,则⊙O的半径等于( )
已知:Fe(s)+12O2(g)=FeO(s)△H1=﹣272.0KJ/mol;
2Al(s)+32O2(g)=Al2O3(s)△H2=﹣1675.7KJ/mol.
则Al与FeO发生铝热反应的热化学方程式为____ ;某同学认为,铝热反应可用于工业炼铁,你的判断是____ (填“能”或“不能”),理由是____
—I've decided to quit this job,but I'm afraid I won't be able to find a better one.
—________.You never know until you try.