A:X的能量一定高于M
B: X和Y的总能量一定高于M和N的总能量
C:Y的能量一定高于N
D:因为该反应为放热反应,故不必加热就可发生
Look!This is my family.
下列函数中哪个与函数y=x相等( )
坐下之前他们握了手。
They____ ____before they sat down.
—Why don't you use your own knife?—Sorry, I've _____ it at home.