读下图中国1月平均气温分布示意图,结合所学完成下列要求:(1)图中AB是我国1月____ ℃等温线。该线以北地区1月平均气温在____ ℃以下,该线以南地区1月平均气温在____ ℃以上;该线大致通过的地区是青藏高原东缘和____ ——____ 一线。(2)从图中可以看出,漠河比海口纬度____ ,漠河离影响我国的冬季风发源地 ____ ,漠河比海口1月的平均气温____ ;海口与漠河1月平均气温相差在____ ℃以上。(3)我国1月平均气温分布有什么特点____
阅读短文,判断正误,正确的在题前打T,错误的打F Helen is an English school girl. She’s eleven years old. Now she and her parents are in Jinan. Her parents teach English in our school. They are very kind. Helen is a good pupil. She’s good at maths. We are good friends. She’s clever and beautiful . Now she can speak a little Chinese.(1)Helen is from America. ____ (2)Her parents are English teachers____ (3)Helen is in Beijing now.____ (4)She isn’t good at maths.____(5)She can speak a lot of Chinese.____
一名射击爱好者5次射击的中靶环数如下:6,7,9,8,9,这5个数据的中位数是( ).
(Ⅰ)证明:BC1∥平面A1CD;
(Ⅱ)设AA1=AC=CB=2,AB=2 2 ,求异面直线BC1与A1D所成角的大小.