but increasing in rapidity and rising to a higher key towards the conclusion. 但是不断增加速度和音高。

　　He sometimes prolongs his strain, when his notes are observed to rise and fall in succession. 有时候棕色麻雀拉长乐段，这样一来它的音调听上去就显得升高和降低错落有致。

　　These plaintive and expressive notes are very loud and constantly uttered, during the hour that precedes the rising of the sun. 在太阳出来的一个小时时间里，这些忧郁和感染力强的音调非常高亢，连续不断。

　　A dozen warblers of this species, singing in concert, and distributed in different parts of the field,  十多只各种鸟儿一起鸣叫，就像一场音乐会，各自贡献不同的声部，

　　form, perhaps, the most delightful part of the woodland oratorio to which we have listened. 也许是我们听到的森林清唱剧里最华彩的乐章。

　　At sunrise hardly a robin can be beard in the whole neighborhood, and the character of the performance has completely changed during the last half hour. 太阳升起时分，知更鸟面临所有邻居的公然对抗，在最后半个小时表演的特点完全改变了。

　　The first part was more melodious and tranquilizing, the last is more brilliant and animating. 第一声部更悠扬舒缓，而最后一个声部则更高亢和生气勃勃。

　　The grass finches, the vireos, the wrens, and the linnets have joined their voices to the chorus, and the bobolinks are loudest in their song. 草地雀、捕虫鸣鸟、鹪鹩和红雀也加入到大合唱中，在这些歌声中属食米鸟的嗓门最嘹亮。

　　But the notes of the birds in general are not so incessant as before sunrise. 不过总的来说，在太阳升起之前这些鸟儿的歌唱是不会停下来的。

　　One by one they discontinue their lays, until at high noon the bobolink and the warbling flycatcher are almost the only vocalists to be heard in the fields. 它们一个接一个地平静下来，到中午艳阳高照时，整个树林里只剩下食米鸟和京燕这两个歌唱家了。