Write questions using the passive. Some are present and some are past. 1 Ask about glass. (how / make?) How is glass made?
2 Ask about television (when / invent?)
3 Ask about mountains. (how / form?)
4 Ask about antibiotics. (when / discover?)
5 Ask about silver. (what / use for?)
1. When was television invented?
3. How are mountains formed?
4. When were antibiotics discovered?
5. What is silver used for?