题目

A．根据句意和汉语提示，在空白处填入一个适当的单词（每空限一词）。【1】It’s important for us to learn English ______________(语法) rules.【2】Tom always works to high ________________(标准), but he is easy to work with.【3】The heavy work has___________________(影响)his health in the past three years, so he looks much older.【4】I want to know if yellow was once the colour of the rulers in _________________（古代的）China.【5】Don’t be so__________________(急躁的). It’s time for your turn soon.在光滑水平面上，一物体以速度v运动．一块橡皮泥从空中自由下落到物体上，与物体粘在一起，则橡皮泥与物体组成的系统在水平方向的总动量和物体最终速度的变化分别为（　　）A．增大，不变B．减小，不变C．不变，减小D．不变，增大