题目选项分析

By pressing a tiny amount of nitrogen between two diamonds to a pressure of 25 million pounds per square inch, scientists were able not only to transform the gas into a solid but to create a semiconductor similar to silicon.

By pressing a tiny amount of nitrogen between two diamonds to a pressure of 25 million pounds per square inch, scientists were not only able to transform the gas into a solid, but they were also able to create a semiconductor similar to silicon.