A:①②
B:③④
C:①③
D:②④
7.8×15+2.2×15=(____+____)×____,这个算式利用了乘法____。
在“探究平抛运动的运动规律”的实验中可以描绘出小球平抛运动的轨迹,实验简要步骤如下:
根据对话内容,从方框内选择恰当的句子填入对话相应的空白处,使对话完整,合乎情景(有两个多余选项)。A:Hello,Mike! What's the time?B:____ A:Where’s Bob? I can't find him.B:I don't think he can come.A:____ B:He has to look after his sister.A:____ B:She doesn't feel well.A:____ Did she go to see the doctor?B:Yes.A:____ B:The doctor said nothing serious,but she has to rest.