This is Mike's bedroom. You can see a desk and a bed in the room. On the desk, there is a backpack and three books. One is a Chinese book, the other two are English books. There is a clock on the desk, too. You can see a baseball under the desk. On the bed there is a box. Can you guess what's in the box? Ah, it's a new computer game. It's the present(礼物) for Mike's seventh birthday.

细菌、真菌等营腐生生活的生物在生态系统中的作用是（　　）

根据所学内容补充句子。

①春天的手抚摸着____，大地一片____。

②春天的手____树梢，枝头传来小鸟的____。

③拉住____，春天就在____。