【单选题】定轴转动刚体角动量守恒的充分而必要的条件是
【判断题】考虑降水背景值,现在一般以pH=5.0作为酸性降水的判断标准。
【判断题】“末日危途”主题科幻小说将“灾变”设定为故事发展的背景之一,现实生活中,人们通常把PH值小于5.6的降水称为酸雨。
【单选题】听力原文:M: Molly gave Lily flowers yesterday. W: Molly just did it for Henry. M: Why did he give flowers W: It's Lily's birthday yesterday. M: Are they on date W: I'm not sure. Who gave Lily flowers?
【简答题】Molly was a peasant girl. Her parents did not have much money and Molly did not have many nice clothes. One day Molly’s father said to her, “Molly, take this pot of milk to market and sell it. You may...
【判断题】酸雨的pH界定最初定为5.0,后来人们提出降水pH背景值这一问题后,又定义为5.6。()