It was about 600 years ago （） the first clockwith a face and an hour hand was made.
举一反三
- —Did you eat yet —（） A: Yes, let's have lunch together B: No, let's go there sometime C: No, about an hour ago D: Yes, about an hour ago
- People decided to honor Edison when ______. A: he made his electric light B: the first invention was made C: he died more than 70 years ago D: the country realized the importance of electricity
- When was the man in New York A: About two years ago. B: About one year ago, C: About three years ago.
- The concept for wireless electrical transduction was proposed about _______ years ago by _______.
- Many years ago he hadwriting a book about his childhood.