Why did Banerjee design his invention?
A:He did it as a hobby.
B:Intel told him to do it.
C:He did it for a school science project.
D:He wanted to get money from his father.
宋元时期是我国历史发展的重要时期,其历史发展的主流与时代特征是( )
某农场为了防止鸟吃草籽,用网把草地罩起来,后来发现草的叶子被虫吃了许多,草长得并不好,产生这种现象的原因是( )
如下图,在数轴上表示到原点的距离为3个单位的点有 ( )