【简答题】Listen to the recording and fill in the blanks with the words you hear. In the past, Brazilian family sizes were much ____1____ than today. In the 1990s, family size suddenly ____2____. What is ____3_...
【简答题】判断下列句中划线部分数字的书写形式是否正确,若正确请填写T,若错误请填写正确写法。 1. This distance is about five trillion eight hundred sy-eight billion miles. 2. A light-year is a unit of length equal to the distance that light travel...
【简答题】判断下列句中划线部分数字的书写形式是否正确,若正确请填写T,若错误请填写正确写法。 1. This distance is about five trillion eight hundred sy-eight billion miles. 2. A light-year is a unit of length equal to the distance that light travel...
【单选题】Thirty percent of the money I get from my parents ____ spent on food every month.
【多选题】关于定轴转动刚体以下说法正确的是
B.
刚体的动能 ,其中J、ω分别是转动惯量和角速度;
C.
不太大的刚体,其势能等于其质量全部集中于质心的质点的势能。
D.
刚体动能 其中m、 分别是刚体质量和质心速度;
E.
刚体的动量 ,其中m、 分别是刚体质量和质心速度