按照泵的作用原理分类，属于动力式泵的有（）。
A．轴流泵
B．齿轮泵
C．螺杆泵
D．喷射泵
参考答案：A
—You look _______. What has happened to you?
—Everyone expected us to win the match, but we lost to the girls. [ ]
A. sad
B. sadly
C. happy
D. angrily
水文循环和地质循环均是H2O分子态水的转换。（）
