With so many exercises ________， the students are having a hard time.

A．finished

B．finishing

C．to finish

D．being finishing

生活中的下列变化属于物理变化的是                                                [ ]

A．粮食酿酒      

B．铁钉生锈        

C．蜡烛燃烧        

D．水的蒸发