可以省略
By pressing a tiny amount of nitrogen between two diamonds to a pressure of 25

million pounds per square inch, scientists not only were able to transform the gas

into a solid, but they also created a semiconductor similar to silicon.
(A) not only were able to transform the gas into a solid, but they also created
(B) not only were able to transform the gas into a solid but also creating
(C) were able not only to transform the gas into a solid but to create
(D) were able not only to transform the gas into a solid but also creating
(E) were not only able to transform the gas into a solid, but they were also able

to create
这题选C 省略了also