In front of our house   many beautiful flowers  when my grandparents were still alive with us.

A．did; grow

B．grew; /

C．had; grown

D．grow; /

使用多重剃刀工具分割多个素材，鼠标移动到剪辑位置，按下（）键，同时单击鼠标左键，当前编辑线上所有轨道的素材被分割开来。

A.Shift

B.Alt

C.Ctrl

D.Del