用科学记数法表示：425000=______．
将425000用科学记数法表示为4.25×105．
故答案为：4.25×105．
胸鳍和腹鳍在鲫鱼游泳时所起的主要作用是
A．产生前进的动力
B．平衡身体
C．在水底爬行
D．控制前进的方向
—_____ did it ______ to get to the nearest clothing store?
—20 minutes [ ]
A, How often, take
B. When, took
C. How far, took
D. How long, take
