当资源不足的时候,物种之间为利用资源而产生的竞争称为 ______ 。
China________ (形容词)
设 x1,x2,xn为样本观测值,经计算知nx 2 =64,
由美国Macromedia公司开发的集网页制作和管理网站于一身的所见即所得的网页开发工具是______。
Ice-cream and candies are not healthy food.They ale u_____ food
《箱子岩》的作者是___________。
Look out of the window.(改为否定句)
______________________________
The boys are sitting under the tree.(对划线部分提问 )
___________________________________________
She is ______ (good) than Alice at swimming.
three__________ (序数词 )