William Perkin was trying to discover __________________ when he accidentally created__________________.
举一反三
- George Crum was trying to make ______________ when he accidentally made _________.
- Ruth Wakefield was trying to make __________________ when she accidentally made______________________.
- What did ancient Chinese chemists discover when trying to find the Elixir of Immortality?
- It is said that he was caught _________when he was trying to climbing into the window.
- Prince William was over 30 years old when he married Kate.