如图,正方形ABCD可以看作由什么“基本图形”经过怎样的变化形成的?____ .
(g取10m/s2,sin37°=0.6,cos37°=0.8)
根据课文内容填空
Daming has got a____. It ____ walk. And it can dance. One day, hey will do____. They will do the housework. They will help children____. But they____do our homework.
利用拖拉机耕地时总比在道路上行驶时速度慢,这是为了( )