利用“I often”造句,至少3句。__________________________________________________________________________________________________________________ 答案:【答案】范例:I often play with dolls.I often clean my room.I often play computer games.【解析】I often play with dolls. 我经常玩玩具娃娃。I often clean my room. 我经常打扫我的房间。I often play computer games. 我经常玩电脑游戏。在一定的时间内,一个自然生态系统内的生物种类和数量一般是 的,生物与生物之间以及生物与环境之间的能量流动和 保持着相对的稳定,这种相对稳定的状态成为生态平衡。