They have this streamlined sternum with lower sternal keels.

它们拥有流线型的胸骨，龙骨突较低。

Birds with a deep sternal keel fly more slowly, those with long sternums are associated with running birds.

龙骨突深的鸟飞得更缓慢，而胸骨长的鸟则大多走禽。

Also, that blood flowing through a VSD can be heard as a holosystolic murmur at the lower left sternal border.

并且，血液流经VSD时，在左下胸骨边缘诊就会收缩期杂音。

Then, if you place a stethoscope in the left second intercostal space, at the left upper sternal border, you can hear the pulmonary valve closing.

然后，你将诊器放左第二肋间隙，在左胸骨上缘，你将肺动脉瓣关闭的声音。

As the blood flows in the reverse direction, the murmur is best heard not in the aortic area, but rather along the left sternal border.

当血液流向相反方向流动时，杂音最响部位不在主动脉区域，而沿着左胸骨缘。

On the other side of the heart, a tricusoid valve regurgitation has similar timing and shape, but it is loudest in the tricuspid area and the sound radiates up, along the left sternal border.

在心脏的另一边，三尖瓣反流有着相似的时间和形状，但在三尖瓣位置声音最大，沿着胸骨边缘向上放射。