Вопрос из теста по предмету Английский язык

Question

Ответьте на вопрос:

What served as a major semiconductor material before silicon?

Answer

In the 1960’s silicon replaced germanium, which was the major semiconductor material until then.

Answer

Silicon was the first material used as a semiconductor, it didn’t have any predecessor.

Answer

Any simple metal was used for mass production of semiconductors.

Answer

Photodiodes were widely used as semiconductors before silicon was discovered.

Ответьте на вопрос: What served as a major semiconductor material before silicon: ответ на тест 406455 - Английский язык