bird的復(fù)數(shù)形式怎么寫

　　例句：

　　1、This species of bird is decreasing in numbers every year.

　　這種鳥的數(shù)量在逐年減少。

　　2、 The area has a wealth of bird life.

　　這個地區(qū)棲息著大量的鳥。

　　3、The lake is noted as a home to many birds.

　　這個湖作為許多鳥類的棲息地而聞名。

　　4、Huge numbers of birds had flocked together by the lake.

　　成群的鳥聚集在湖邊。

　　5、 The male and female birds take turns in sitting on the eggs.

　　雄鳥和雌鳥輪流伏窩。