There are two ways to make these machines,but_ it worthy of note.
问题描述：
There are two ways to make these machines,but_ it worthy of note.
A.a first B.one C.the one D.the first
答
选D
There are two ways to make these machines,but_ is（不该是it 吧） worthy of note
the first后面其实省略了( way to make these machines)
意思是：有两种方法可以制作这些机器,但是第一种更值得注意.