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，你将听诊器放到左第二肋间隙，在左胸骨上缘，你将听到肺动脉瓣关闭的声音。

If you place a stethoscope between the second and third rib, known as the right second intercostal space, just next to the upper border of the sternum, you'll hear the aortic valve closing.

如果你将听诊器置于第二肋及第三肋之间，被称为右第二肋间隙；紧靠胸骨上缘，你将听到主动脉瓣关闭的声音。

The midclavicular line is the imaginary line that gets drawn from the midpoint of the left clavicle, or the collarbone, straight down, and you can find where it intersects with the fifth intercostal space.

锁骨中线是一条从左锁骨中间位置笔直画下来的假想线，你可以找到它与第五肋间隙相交的位置。