①偷税行为 ②欠税行为
③抗税行为 ④骗税行为
A:①②
B:③④
C:①③
D:②④
在探究“凸透镜成像规律”的实验中,已知凸透镜焦距为10cm,当光屏上成一缩小倒立的烛焰的像时,烛焰与凸透镜的距离为( )
—You are relaxing yourself here?
—Yes. It feels ____ to walk slowly along the river.