First, play the entire piece using to. Note that Bach inserted a maximum number of thumb crossings so that we have plenty of chances to practice them - obviously an intentional construct.

首先，运用拇指跳指法弹奏整支乐曲，不难发现，巴赫设置了一个拇指交叉的最大值，这样我们就有充足的机会来练习他们——显然，这是一个匠心独运的构想。