如果考试没考好,心情郁闷,下列调整自己情绪的方法错误的是( )
现有化学反应:xC2H6+yO2zCO2+wH2O,化学计量数之间关系正确的是( )
It was not until dark ___ he was aware of ___ he thought was the correct way to solve the problem.